The only reason they changed the way setimes were acquired was to make sure the more experienced raiders would join LFR to improve the chances of the tourists (i.e those who have zero clue about boss mechanics, don't put any effort into learning them either and who have no idea how to proper play their toon). On top of that loot distribution was completely random, so that the chances of getting what you wanted was much bigger provided you ran it with friends or you had good begging skills/something to trade.
So yes, heroic raiders in the past were forced to run LFR.
Luckily this changed with MoP. I find it perfect nowadays. There is no need to run LFR to cap out on valor if you don't want to, there is no need to acquire gear if you just stick to dailies for alts and the personal loot system made it such that it's no longer absolutely needed to run it.
I do no longer feel forced to do LFR since I have options. Whether hc raiders still do it depends on the person. Half of my guild still runs it every week on alts or to cap VP on mains, the other half like me absolutely hates to clear the same instance more than once and stick to some heroic dungeons or dailies to cap out. And options are a good thing.