I don't know much about comic viewers and buyers.
But, I do know that BtVS ratings went down in the later seasons (the heavy Spuffy seasons). Yet, the writers still felt condemned to write more Spuffy because of fans who pitched fits over the couple (I'm not saying anyone on this board did that/does that, but it is well known that some Spuffy fans were very demanding and even threatening over their ship.)
This exact same thing happened with The Vampire Diaries. S1-3 had the highest ratings when Elena was human and dating Stefan (their version of Angel). Then Elena begins dating Damon (their Spike) for basically the remainder of the show. Elena becomes unrecognizable, that's how OOC she was. The storylines begin to not make sense just to make this couple happen. And during all of this the shows ratings are pretty consistently dropping. Hmm this is beginning to sound familiar? Yet, the writers continued this relationship due to demanding and threatening fans as well as the writers supporting for some odd reason. I've spoke to some Delena fans on youtube, and they are down right nasty to you when you do not agree with them.
It just baffles me that writers always give in to the loudest, most demanding and threatening fans instead of staying true to their story, keeping their characters in character, writing fantastic storylines, and having an interesting relationship that does not consume the entire show. In scifi, fantasy shows, the relationship should not be the main focus,; the storyline, message, and characterization should be, but writers seem to forget this for the sake of a toxic ship. AND IT IS ALWAYS FOR THE TOXIC SHIP. I will just honestly never understand how a man treating my heroine like dirt and constantly having sex is more interesting than two lost souls finding each other and treating each other as equals while having real obstacles yet still trying to make it work. I just DO NOT get it.