Client stuck on loading screen while game starts for everyone else

Client was stuck on loading screen showing me at 100% and other people at 0~75%. Game eventually loads, with 3 minutes into the game. Game lags horribly and doesn't stop skipping until a reconnect is performed.

Why does the game start if everyone hasn't finished loading yet? Why is there no warning that the game has started (your client has timed out) and that the player should restart their client to attempt to get back into the game?