the reason to think BART for Geary is that Muni has consistently failed to do anything. And, secondarily, a Geary route could,if money and brains aligned, include a west side N-S crosstown connecting from Daly City past Geary to (gasp) the bridge. The custom purchased engineering crap from the 60s can be contradicted and despite all of the NIMBYs we could finally get seriously convenient and useful subway service. to Marin.
As to the ghetto comment, the needle crap will have top be sorted out in the near term; in my view a first step might be forcibly shooting the losers up w/narcan (sp?) to wreck their highs until they either quit or leave town.