Yes I agree however you need to keep in mind that most likely in 2 weeks or one month. BTC might be around $150 or so.
That's the reason why many are selling their S3/S5 hardware because they are afraid that after BTC crashes hard, they will lose money.
Currently for most the hardware is profitable but might not be in 2 weeks.
I must disagree, bitcoin price shouldn't matter, if it does, it simply shows that one is not in it for the right reasons and is only seeking a profit, and not for the good of the system. I currently have 1 machine, I can either sell it for .5 bitcoin, or I can mine with it and earn 1 bitcoin (example), price doesn't matter if I am seeking to have more bitcoin. Of course your rebuttal would be, "what about electricity cost? That can't be paid in bitcoin" and I would refer to the fact that I am currently heating my apartment with these machines, which is a more efficient way than heating with my furnace, so it balances out, that may not be the case for someone else. Everyone has their own calculations, mine include not worrying about electricity cost in the winter, and not worrying about the bitcoin price, as I am in it for the long haul.