In terms of results at Sochi, there's no reason to think Polina shouldn't have gone. She performed well there--placing higher at Sochi than Mirai Nagasu did at PyeongChang.
The real problem in 2014 is that Ashley bombed one of her skates--she was given an Olympics spot because her performance at Worlds had helped ensure three spots for the American Ladies. If she'd skated better at the US Championships, it wouldn't have been an issue. But she didn't.
She didn't bomb her skates in 2018, but by then the three spots were due to Karen Chen's perfomance at Worlds, so Ashley, in that sense, wasn't owed a favor. Chen, on the other hand, had delivered a clutch performance at Worlds.
The thing about you Ashley-ites is that you want it both ways--you wanted Ashley to get the benefit of the doubt in 2014 (which she did), but resented it when Karen Chen basically got the same thing in 2018--and Karen's Nationals performance in 2018 was better than Ashley's in 2014. There was no sign, last season, that Ashley was on upwards trajectory--she wasn't. She was using old programs; her PCS was good, but technically she was falling behind other top skaters. And her PCS wasn't at the level of a Kostner's, she's not one of the great artistic skaters.
I like Ashley's skates--I liked her Silver performance at Worlds, but I get tired of how Ashley's defenders trash other skaters because they think their girl was shortchanged. Polina Edmunds comes up because her silver placements at Nationals both happened, in part, because Ashley struggled with one of her skates. Doesn't mean Polina had no business getting second or going to the Olympics. Or that Ashley wouldn't have solidly beaten her on another day. But that's how competitions on ice work--they're not fully predictble. Karen Chen fans don't trash Bradie Tennell for her winning skates, even though they may not like how Bradie skates as much as they like the way Karen does, but I don't feel like she's trashed in the same way.
It's fine, IMO, to feel a skater is/was underappreciated and say why, but the ongoing harping about Ashley not getting this or that has gotten real old.