I understand your point that you're trying to make, but it's a difference in opinion.

Just because you bought the game doesn't give you the right to access any server at any time, especially if it's full. You're paying for the engine. For example, a server can rightfully ban you for absolutely no reason at all just because the server owners pay for that server.

By paying for a slot on the server at any given time, you're helping pay for the server and it allows you to access it any time. The server owners, for a long time, have elected to let no-steamers play with steam players, so in this regard there's no difference between a steam user and a no-steam user. You're still differencing between the two, but in the way the server is run, there isn't. The only difference is between players are admins, reserved slots, and regular players. As far as I know and remember, a no-steam player can also purchase a reserved slot.

As a side note, I think you grossly underestimated the amount of no-steam users that we have on the servers. 99% of users are not steam users, I'd say maybe 65-35, maybe even close to 55-45.