Fair enough. Personally, I prefer personality over appearance. But I also think it's a visual turnoff to see no effort, also because the way a person dresses is usually the first thing most people notice. I do, anyway.
Everybody's already mentioned the important things, but to be the more superficial one: people with no sense of style. People who just throw on something randomly and don't give it a single thought. I get being comfortable, but you can be stylish and comfortable. You are not that when you wear knee-long jeans shorts and an unwashed tee, in my opinion.
I still use services like Spotify, FB Messenger, and Play services for some of my banking apps. I'm a bit new to this whole privacy thing and custom ROMs, but so far it feels good. When I buy a computer I'll install Linux on it.
Like others have said, don't think too much about it. It's really not that big of a deal to greet your colleagues. If you insist on doing so anyway, do it because you want to, not because you expect something in return.
That's what I've been experiencing too.