I'm not bothered by the licensing issues mentioned, and I'm ambivalent about the namespace issues, but I've been increasingly uneasy for some time now about Mint's security practices. Serving downloads over http and not providing GPG signed SHA hashes like every other distro is fairly irresponsible in this day and age.
This recent security issue, and the poor response to it, are basically the straw that breaks the camel's back for me. I'm moving on to Ubuntu-Mate, since frankly Mate was the primary reason I was using Mint anyway. Serving downloads of the most popular Linux distro from the same machine as is running WordPress is cringeworthy, and failing to take the compromised machine totally offline until it's 100% sure the compromise has been mitigated (through reformatting, including boot sector) shows really poor judgment.
I'm a bit sad to be so critical, since I recognize that Clem has done a lot for the Linux world, and as a Mint user I've benefited personally from his work. But when you're distributing operating systems to so many users, you have to take security seriously. To do otherwise, even on a "hobby" project (although I'm fairly sure it's his full-time job now) is pretty irresponsible.
In many ways, I'd like to pitch in, but based on other interactions I've seen and read about, I'm not sure my input would be welcome, particularly wrt security issues.
Edit: I'm also playing around with FreeBSD for my development environment, since I can use Mate on there. To be honest, I don't really need a DE these days anyway, since I only use terminal and a web browser. I should look into just using a Windows Manager.
Edit 2: Apparently they do provide GPG signed hashes. I've been looking for them each time I've downloaded Mint distros, but never came upon them. So I stand corrected.