An interesting aspect to the Hallmark changing their minds story is that Zola was ready yo pull ALL their advertising from the various channels. I mean their decision smacked more of a financial one than a principled stance, but the threat they must have faced was likely significant.
They also have so much more competition from other networks, as has been mentioned. They were pioneers in this type of cheesy, saccharine Christmas movie fare. But as with all pioneers, you get eclipsed as newer and better brands get introduced. Hallmark was destined to decline whether or not they have gay characters looking at each other in a movie or not.
If it's really that serious for these groups, as someone noted above, why not start their own channel - all white, hetero, 1950s gender roles movies which will not play any upsetting ads ever? Seems simple enough to me.