My opinion? It is my assertion that only a small percentage of those who watch ROH pay attention to the storylines/gimmicks/angles.
No offense, but my opinion is that your assertion is absolute bullshit.
The "hardest of the hardcore" fan that you speak of is someone who appreciates all the aspects that are needed to produce a great product. Sometimes great matches can be just that and they don't need largely developed backstories, but it doesn't work the other way around, a great build without a quality in-ring payoff is a waste of a great build. The converse to that is if you only have great matches but none of them ever have the proper build you aren't giving enough people enough reason to care. Even hardcore fans of the in-ring product still want purpose for the matches to get them invested.
Hell, look at the UFC, even they try to portray the real life "storylines" behind most big fights, because they know more people will care. Even a hardcore MMA fan wants to know any personal reasons that may exist that make the fights more intersting.
I would assert that only hardcore NFL fans watch the hundred hours of NFL coverage presented by NFLNetwork, ESPN etc. leading into every weeks action, and those shows are as much about the week's "storylines" as they are about game analysis.
Hardcore fans care brother. That is fact.
A perfect example for ROH is happening right now. ROH is about to head into its biggest show of the year, and the world title challenger hasn't appeared for the promotion in months. Yet, somehow, more people are excited for this match than any of Steen's title defenses. Why? Because most of Steen's defenses have been against guys that are only placeholders in ROH management's attempt to take Steen's belt. None of them have been built up for the challenge with significant interaction with Steen.
So what's the difference now? Why is it that EVERY true ROH fan is beyond hyped for Final Battle and a defense against a guy that Steen beat in the spring and who has been gone since? Easy...
because the match is the possible culmination of the most compelling, coherent, well-conceived, well-written, and consistently well-executed longterm storyline to play out in wrestling in over a decade.
Would Roddy against Elgin be great with no storyline. Sure. Is it better because there's a great storyline? Much. Is a tag match with O'Reilly on one side and Davey on the other almost a lock to deliver? I'd say yes. Is it even more sure to deliver because of a good slow burn of animosity? Yeah. Would anyone at all care about a match between Cole and Hardy if ROH had not attempted to build some angle attached to it. Not likely, and even more to my point most still don't care; why? because the angle is so badly conceptualized to begin with(to the point of the thread its another bad example of Cornette's shitty booking, but Delirious is backed into the corner and can't not present the match now).
Would a Steen/Generico ladder war be a potential classic with zero build? Likely. Does the fact that its ten times more personal than say the matchup between Roode and Storm at Lockdown or BFG could have ever hoped to have been make it that much more awesome that the expectations are blown through the roof? Hell Yes. Because a storyline like this means everything. Especially to the hardcore fan.