They used to be, but FSA is a term not used often anymore in the field, that group shattered into other groups. Now they're : Ahrar al Sham, Liwa al Islam, Islamic front etc.
If you ask me I think it wasn't a right choice to Islamify the opposition, they've disbanded secularism to take on 'moderate' Islamism that recognizes borders. This leaves the secular former FSA fighters without a choice but to return to SAA. As for Islamists they have the choice between Nusra, Islamic front and the more popular non Syrian ISIS, they were better off with a secular ideology.
Everyone claims that
That'll destroy the entire foundation of the opposition, most Islamists will go to ISIS, most wanting a 'free Syria' as they call it lose all hope in that group as soon as it abandons secularism forcing them back to SAA.
You clearly are misinformed.
FSA is still very active, for example, the Southern Front, which have been destroying Assad's forces in Dara'a, Quneitra, Damascus (it's coming...soon Inshallah.)
Ahrar al Sham and Jaysh al Islam (formerly Liwa al Islam) were united under the Islamic Front, along with other groups. Now, the Islamic Front are united with more Islamist groups in an alliance called the Levantine Front. Jabhat al Nusra is not included in this group btw.
Uhm, FSA would never return to SAA. Some FSA members were communists, and yet, they never went back the SAA. Yes, this is a war of ideologies, but this is something you don't understand. Just because one is secular and the other is Islamist, doesn't mean they won't co-operate. They are mostly Syrian. They want a Syria free from tyranny and outside puppet control.
Yes, everyone does claim that. But if Allah wasn't on our side, we'd be destroyed by now. We held out up until early 2013 without much foreign support, and we're going much stronger now. Assad got his foreign suppliers, and now we have ours. And you can clearly see who is making the advances, despite a clear disadvantage in sophisticated weaponry.
Most Islamists go to ISIS? The Levantine Front and Jabhat al Nusra would like to have a word with you. While Jabhat al Nusra are extremists, the Levantine Front which is ~90,000 is plenty capable of taking out ISIS. They are however, focused on the true enemy here, which is SAA. ISIS killed less than 10,000 in their existence, while Assad killed multitudes more. ISIS is the tail of the snake, Assad is the head.
Again, with that retarded "forcing them back to the SAA" argument. As I have said before, many rebels have varying ideologies, and they are united in taking down Assad. FSA have already laid out a political plan after Assad's fall, most rebel groups are fine with it.