Also looking at things like pirate sites, it would be never ending process. Close one and lock the their inventories and 3 will popup somewhere else. It is unlikely to be solvable issue.
Just because you cannot "solve" an issue, does not mean you should do nothing. By that logic valve should not implement VAC, because after all, cheaters will always find a way.
They play the anti-cheat game of cat and mouse, because if they do not, users will stop playing. No one wants to play with cheaters unless they are cheating.
They could definitely invest some resources into this. But they have no monetarily incentive thus they do nothing. I fully expect legal action or fear of it, will eventually make them do something.
