It’s less that any one particular thing breaks instantly, and more that it destabilizes the system in general. Mac installers often contain shell scripts, for example, and those scripts are going to assume that the core OS tools being invoked by those scripts are the ones that shipped with the OS. Software updates and all sorts of other under-the-hood things contain shell scripts or make assumptions about those tools, their behaviors, and how to invoke them.
Imagine taking an Ubuntu box and overwriting every single core utility with a recompiled version of the utility of the same name from OpenBSD. You might think that’s a bad idea- same reasons, same risks. Sure, everything might work (and probably will), but it’s fundamentally destabilizing a working system.
And for what benefit? Just so some developer doesn’t have to be bothered with learning the differences between GNU and BSD runtimes? That just seems like a terrible tradeoff, and I wouldn’t want to work with someone who both didn’t know the difference and couldn’t be bothered to learn.
Like, if someone can’t be bothered to learn the OS that they’re working on, then there’s a simple solution: don’t use that OS. But if getting something done on that platform is a requirement, then they should take the time to do it properly, and beyond entry-level people I would simply expect any developer worth their salt to get their job done on the platform they’re developing for or deploying to. It’s not a lot to ask, it’s not a high bar, it’s a pretty reasonable expectation for a professional. People shouldn’t half-ass something like that just because they think they are too special or precious to spend time learning how to do their job.
EDIT: if it’s not obvious, I’m specifically talking about developing for a given platform in a professional capacity. I don’t care what people do for fun or education or hacking around- not unlike using a Hackintosh or jailbreaking a device. I don’t mean to sound judgy or anything (outside of a > entry level professional context).
