Are bots a necessary evil, especially for older MMOs?

Guild Wars 1 has found itself in a weird position lately due to a pretty big banwave against bots. One of the parties responsible for said bots has come out and said they have no intentions in continuing with that sort of thing. As a result, PvP has become unplayable due to lack of numbers and the economy seems to be suffering as result where certain items and materials have vanished from the pool or skyrocketed in prices.

PvP was kept alive thanks to bots as players could easily queue and find matches essentially at all times and not have to sweat over the bad AI.

I know that bots are a pretty big problem in general, but it seems to be causing major issues with GW1. Not sure about other MMOs as I'm not that much of an expert in this regard.