It has always seemed to me that without the marketing led North American bubble - all those sweet cost plus deals handed out to Regionals in the 90s (but we gotta have jets people like jets). The 50 seat RJ (and especially the 35 & 44 seat scope-mobiles) would have had a very limited appeal almost niche in fact. That bubble has now burst as fuel and other costs bit and the franchises are much tougher deals
Just look around...CRJ200...gone 145 on it's way out production wise.
The tide has turned no doubt about it...Again a few years ago most of the airfields in SW France had a few ATRs stashed by the company hopefully a bit out of sight. There were a bunch behind some old farm buildings at Toulouse where the 380 sheds are now as well. Today they are all on lease everyone of em.
For example I passed through Houston a couple of weeks back...if you'd a looked at that ramp (term B) four years ago it would have been Jungle Jets as far as the eye could see (plus round the other side), sure there were still a fair number around today but also an awful lot of S340s (also in CO Exp/Connection colours) I believe they also have 1900s, ATRs and DH8-300s on franchise too at other hubs - what's more there were a signifiacant number of 145/135s parked in these aren't going anywhere for awhile manner between the Fed Ex and Express Jet hangars.
End of the day its the beanies that call the tune and the beanies like T/p costs.