Kicking one or two quiet people could be alienating, yes, but when you have a full room and not one of them is talking to you or responding to your efforts to make conversation, it can be highly frustrating.
Now, on Streammate, the room counts are vastly different from those on token sites, of course. I usually only have 1 or 2 guys in my chat, plus however many are watching without accounts. They usually at least strike up some small talk when they come in, even if they don't stay for a private. A lot of the customer base on SM is looking to take a model private and get off, some without chatting first, some after striking up a short convo, so room counts aren't as important. Most guys, in my experience, enter my room, small talk with me for a minute or two, ask me if I'll do xyz in private, then either take me private or move on to a model who offers what they're looking for. My room count has absolutely no effect on this. I've never experienced a room full of silent dudes on Streammate, but I've had 75 people in my Chaturbate room once, without even the "open bobs bb" goobers speaking, and after trying and failing to get them to say ANYTHING - how was your day, any plans this weekend, you guys wanna see my tits - I've said it was time to go to bed and logged off, because I have yet to have a silent goober night become profitable there. Streammate is a little different, and I can totally understand kicking a room full of silent dudes there. I'm sure a potential viewer would rather see me smiling and jiggling my butt to an empty room than trying to strike up a hopeless conversation with a full room, which would leave me visibly annoyed despite trying to plaster a happy demeanor over it. I fidget by jiggling and flexing my glutes, and doing this while smiling and surfing the net gets me way more privates than having a full room ever does.
Yes, some models run a pretty social room on Streammate, and a higher room count could benefit them. However, that dynamic doesn't work for everyone, and some of us really benefit from a smaller, more intimate environment.