Do we really need to be so constantly cringy about it? Yes, custom ROMs are great. I run one. Lots of other people run one. They’re great. Don’t get me wrong. But you have to realize most people simply don’t care for one, Most vendors also don’t really support their phones well under GSI, so things like camera and stuff like that hardly ever work properly.
In a lot of cases, it is quite a bit of work to get a custom rom flashed and have it working well. The technological skill gap between most people who will run an Android phone and even enthusiasts who will so much as think about installing a custom ROM is so massive that you may as well be a hacker to them.