Indeed. There are few environments less well-suited to BJJ than, say, a bar fight- where you're potentially up against multiple attackers, armed with various weapons.

The other area where I think BJJ needs a lot of work is in the area of weapons defences. I've seen and heard of BJJ practitioners arguing that one can roll with a guy with a knife, on the ground, in close proximity. That strikes me as sheer madness and shows a lack of understanding of the concept of a knife defence- which is clearly a defence against a short, sharp object, and therefore such an object needs to be kept as far away as possible.