They are able to tell us how successful their efforts against botting are, but elect to not provide that information (sensibly) to us - but have made a statement here:
Greetings Commanders, Some of you have expressed concerns over suspicions of bot usage in Elite Dangerous. Frontier is committed to offering the best gaming experience to all of our players and we actively monitor and act on any developments that might unbalance the Elite Dangerous Universe, or...
forums.frontier.co.uk
To provide us with their stance.
As for griefing... That is written into the game description, and is easily avoided - why remove one playstyle when being 'content' for it is a concious decision?
(Although I'm 100% behind having both PvE & PvP 'open' choices) - I'd enjoy meeting up with some 'names' on this forum for even more co-op fun - I play with only a few currently.