On several projects I've been on, I get issues or pull requests proposing to change the entire build system of a project. As you know, for C/C++ projects, the build system can be non-trivial, and maybe many years have gone into getting it to work well. And as things change, we adapt it. But as soon as it's not the flavour of the week, you get github requests suggesting to change to a completely different one, to suit some or other system's needs.
A tweak here, a tweak there, or an entire overhaul being proposed from people who haven't contributed to the actual code base at all. These infrastructure "suggestions" from people who aren't invested in the project but love to play with scripts built up "around" the code get very annoying. I don't know what the difference is exactly but it didn't happen with such frequency when things were more oriented around mailing lists.
I've now got 3 projects that have at least two build systems each, because of random people's preferences. That is a lot of extra work to maintain that is orthogonal to the actual project source code. I've started closing PRs that make infrastructural changes that I don't want to be responsible for, unless I can get the submitter to promise he'll be around for a while to maintain it. I've also started forcing people to put such changes in subfolders so that it's clear which one is the "supported" system. And I haven't shied from "assigning" subsequent bugs back to the original PR submitter. But sometimes that doesn't even solicit a response.
People: if you are going to suggest switching a project to a completely different build system, and then disappear and not promise to maintain said system, please think twice about changing something just because it doesn't suit your preferences of the week.