FC costs several times what coach costs.

Why should an airline , give these away for free?

If you buy a camry from toyota and the dealer has 50 or so avalons on the lot, do you expect to be given an avalon?

Of course not.

So why, when you buy a coach ticket, should you expect a first class seat?

As for Bosox's situation about people taking up extra seats. Did you expalin the situation to a F/A and ask for assistance?

Also, if a flight is very empty, when you check in, you can ask for a seat with nobody next to you. I've done this many times.