Why systemd?

The author is not making any mistake at all, or no more so than you are.

I'm sure you both value engineering principles like separation of concerns and a single source of truth.

The author believes that by removing the redundancy between initd / xinetd / supervisord / syslog the system is improved.

You disagree, and believe that these are separate concerns.

That's fine, you have different values / judgements in this matter. But saying he's `mistaken` for not agreeing with you is childish.

While I am not an expert on legal language and how it can be used by lawyers, I believe RMS and the FSF at least attempt to address this in the GPL Version 2 (there is probably a similar requirement in the GPL Version 3, but it is more complicated so I'm not sure which requirement corresponds to this quote form v2):

"The source code for a work means the preferred form of the work for making modifications to it."

Code that is so large complex that it is not practical to understand or port wasn't written by a human. Such code is probably a template or macro expansion of the real source, and the "preferred form" would be the pre-expansion source.

This may not cover all ways of obfuscating the code, but "preferred form" is trying to be as inclusive as possible.

In a server environment it happens that the various DRAC/BIOS(es) are initialized and the bootloader reached is far longer (several minutes sometimes) than the boot time of sysvinit. So optimizing boot time in the Linux part on a server is probably moot for me.

On the laptop you can suspend/hibernate as others have said if you care about startup time. I have full-disk encryption and need to type in password to boot so few seconds more or less doesn't matter anyway.

So that leaves the desktop, where I might care about boot times (the UEFI/BIOS is actually saner than in servers and reaches the bootloader very fast). It turns out that my desktop boots faster than my router with sysvinit already, so having faster boot times on my desktop would get me nowhere, I still wouldn't be able to use the internet until the router has booted.

So faster boot times ... I didn't need all the pain systemd is causing just for that. Debian has haid makefile/startpar based concurrent boot already, I don't think systemd would improve on that much ...

Meanwhile not using systemd breaks things that used to work on a KDE desktop (USB mounting, VPN config, etc.), so having an app support systemd is a net-negative for me.

For starters, as an example, I have 100 times as many servers than I have desktops to deal with - for a lot of us Xorg is not an important factor. But the process manager is vital to all of them - server and desktop alike if you want to keep them running. If the process manager fails, it doesn't matter if it wasn't Xorg that took things down.

Secondly, that X clients fail if the server fails is not a good argument for moving Xorg into pid 1 too, because it would not solve anything. If pid 1 crashes, you're out of luck - the best case fallback is to try to trigger a reboot.

Having (at least minimal) process management in pid 1 on the other hand serves the specific purpose of always retaining the ability to respawn required services - including X if needed. (Note that it is certainly not necessary to have as complicated respawn capabilities in pid 1 as Systemd does).

Having Xorg in pid 1 would not serve a comparable purpose at all: if it crashes, the process manager can respawn Xorg. If you then need to respawn X clients, and be able to recover from an Xorg crash, there are a number of ways to achieve that which can work fine as long as your process manager survives, including running the clients under a process manager, and have them interface with X via a solution like Xpra, or write an Xlib replacement to do state tracking in the client and allow for reconnects to the X server.

Desktop recoverability is also a lot less important for most people: Every one of our desktops have a human in front of it when it needs to be usable. Most of them are also rebooted regularly in "controlled" ways. Most applications running on them get restarted regularly. People see my usage as a bit weird when I keep my terminals and browsers open for a month or two at a time.

On the other hand, our servers are in separate data centres and need to be availably 24x7, and many have not been rebooted for years, and outside of Android and various embedded systems, this is where you find most Linux installs.

While we can remote reboot or power cycle most of them, with enough machines there is a substantial likelihood of complications if you reboot or shudder power cycle (last time we lost power to a rack, we lost 8 drives when it was restarted. Even with "just" reboots there is a substantial chance of problems that requires manual intervention to get the server functional again (disk checks running into problems; human error the last time something was updated etc.)

That makes it a big deal to increase the odds of the machines being resilient against becoming totally non-responsive.

Exactly! What the binary log advocates seem to be missing is that those unclean shutdowns (often called "crashes") are probably the very thing you are going to want to search for the in log. In general, few people care how (or if) log stores that the cron daemon yet again ran the hourly maintenance without any errors. What everybody who has had to search a system log cares about is "what happened right before the crash happened".

The current data that needs to be committed to the log successfully and immediately almost by definition happens at a time when you do not have the time for the complexity of an atomic addition to a database. Often there is barely have time to any disk write at all.

The only way make the system log useful would be to make adding events synchronous. As nobody wants to deal with a syslog that is 10,000x slower (or worse), the only sane option is what we always did - make the writes simple and immediate, and defer any fancier feature.

Have they never heard of "log parsers" before? If you want it in a search able DB (which can be very useful), you do that from original log either as an async daemon or defer it with cron or similar.