I've been working on and off with Make, C, autoconf, etc for ten years. Maybe if I were a full-time C or C++ person I'd have less trouble with this, but it seems rather excessive. The thing that most discourages me from contributing to certain open source projects is when I clone the repository and the build fails and I can't get the project to build in an hour or less of build-debugging time (and I'm not on a weird setup, I'm on a modern Lenovo with Debian).
Worst case scenario, the SlackBuild I'm writing has to include some call to patch or sed in order to tweak the installation path, or I just have to cp the build output into the package's root directory (something which I'll likely have to do when I get around to updating the CouchDB SlackBuild, but have been putting off since 1.6.x works well enough on Slackware).
Though I don't see the point in reinventing your own build system, exactly. Some people I trust seem to be getting into Meson these days but I havent tried it.