It seems that while Valve had everyone's best interest at heart when they made Team Fortress 2 free to play but the community disagrees and have already installed a plugin that kicks the "free" players in order to keep room on the server open for the "Premium people"

A number of servers both public and private have already implemented a free plugin which can be found HERE which helps reduce the number of free players on the server to 0/32 or 0/64. Since the game isn't available for sale anymore the only for free players to get past this plugin is to do a microtransaction off the in-game store and then they will counted in as a premium player.

To be honest I was worried about having to wait to get in my favorite servers now that the game is free but most of the servers I play on have this plugin and I never have to worry about a freebie taking my slot, but I can sense that this will definitely discourage free players and soon enough most if not a lot of these players will probably go back to their Counter-Strike or Call of Duty gaming rather than having to cherry pick a server every time they start the game. I mean wouldn't you be tired of jumping server to server only to find one which doesn't automatically kick you after a certain amount of time?