Just take, say, Chess tactics ladders, for instance. They can't really do anything about Rybka-backed bots; if there's enough computing power, someone can just leave their machine on with a connection and see how high it gets.

The only way they can stop that is to ban obvious abusers every time ...

Why would a 1v1 player have to do that? It increases the workload, sure, but right now, you can play on small maps and have one player suicide all the neutrals and open themselves up for another.

The exploit is still there.

Without a resign button, people are discouraged from playing this game ...