I'm sure that the server would have more than 30 thousand people playing simultaneously, if it was 10 years ago I would even understand the limit reason, after all the technology was not advanced like today ... but nowadays I'm sure it's possible host a server with support for thousands of players and so the question: Why limit the amount of players on a server?
I have never seen an official server pass from 6 thousand players (it may have happened, but at the moment, for example, it did not happen)
Why not go from 6 thousand players per server? Why multiple servers? Why not only 1?