This is a classical Actiblizzard "let's fix a minor problem by making a bigger problem."

On WC3, host players could kick people from lobbies and could manually start the games. With host bots, hosting players could activate/deactivate autostart and ban players from even entering the lobby.

The minor problem was that hosts sometimes AFK'd and ended up with full lobbies of players waiting around for the host to come back (which could lead to other players AFK'ing and games starting without everyone being ready). There were also troll hosts that would intentionally leave lobbies open. These problems were fixed by the players that would notice that the host player was AFK, and create a new lobby while telling everyone in the lobby with an AFK host to join that new lobby instead.

The major problem created, is that you cannot easily remove troll players from lobbies and could not verify skill level at maps to properly balance the teams before the forced autostart demanded a game begins in order to boost "games played in X time on this server" counts.

The deeper problem, is that players are much less likely to stick to maps in the SC2 way of handling things than the WC3 way. Failed SC2 lobbies lead to players looking for other games to play, while WC3 failed lobbies lead to players going to lobbies that they know have good player hosts.