Well, networking always requires some sort of client software, calling it "clientless" because most systems most likely already have the required software rubbed me the wrong way.

But I think I get it now, it's probably a tongue in cheek reference to "serverless" :P

I'm with you. I was confused by that term. Why not 'browser based remote desktop'? I've never heard anything happening in a browser called clientless before. In fact it is usually explicitly called a client, e.g. client side rendering.

That’s a good point. Avoiding calling it browser based and using a euphemism like client-less probably should have annoyed me more.