Bolded: Oh please, who in Thedas doesn't idealize their former culture? What nation/religion/former empire doesn't look on their own history with rose-colored glasses?
The dwarves of Orzammar look fondly on the time when they were a vast underground empire with Deep Roads and Thaigs that spanned all of Thedas, and obsessively try to keep that old ideal alive by holding fast to ancient traditions even though they're no longer apply, and like to act like they're still proud, superior, powerful bigshots even though they're vastly outnumbered by the other races (1 dwarf for every 100 humans), suffer mass infertility, and have only two known city-kingdoms besieged by darkspawn.
Tevinter is not only no longer the vast empire that holds the whole known world in an iron grip, but they were the ones that screwed Thedas over as badly as it is now. (Bringing darkspawn and all, which was "not us" as Dorian says; killing Anstaste, which they figure was "just a mage" to make themselves feel less guilty, as Dorian says). But they still like to pretend that their loss of most territories in Thedas and their current deadlock with Qunari are just minor setbacks that will soon be overcome and they'll be as grand as they were before the Blights.
And need I go into the Chantry trying to act like non-magic, Maker-worshipping humans are always perfectly sweet, loving, accepting, and reasonable, and that all problems in the world are always the result of mages and elves and heathens, and conveniently censure positive mentions of mages and elves in Andrastian religion and history?
But yeah, sure. Only the Dalish idealize their past, spend lots of time trying to rediscover and reclaim their lost culture and/or former glory, and are the only ones who can sometimes act like obnoxious brats about it. (And of course all Dalish are obnoxious brats without exception. Opinions and attitudes about it don't vary from individual to individual, group to group, clan to clan within Dalish culture the way it does for individual dwarves or Tevinters or Andrastians. All Dalish have one big hive mind of obnoxious past-romantization and obsession.)
The Dalish don't idolise their past. They've turned their past into a religion. It's impossible to separate out their history from their faith. That the elves were once immortal is a historical claim - but to the Dalish it is also an absolute tentent of their religious faith. The same applies to their (really racist) ideas about the quickening. It's a historical claim couched in cultural superiority turned into a religious belief. This is far more than just the veneration of the past. Their whole culture is defined by this attitude. It's what it means to be Dalish. And it's what Solas so vehemtly dislikes about them.
The dwarves don't worship they past. They worship their forbearers, but it's an open secret that the Shaperate actively manipulates history. They know it as they don't acknowledge it. It's not religious.
Tevinter is the most cultural in its veneration of the past - they pine away for a past glory that may not exist. But they won't worship themselves or ancient Tevinter.
The Chantry is the most hypocritical of the religions because it not only combines a kind of historical/religious narrative to Andraste but they manipulate it over time in a way that the elves don't. The Chantry clerics are every bit as hypocritical. The only difference between them and the Dalish is that these ideas aren't as central to the Chantry as they are to the Dalish.
You seem to somehow think that calling the Dalish out on their self-righteous hypocrisy means absolving other races of their own faults. It doesn't. But this isn't a thread about comparisons, though apparently it's impossible to avoid the topic if I'm not being absolutely tripping over myself to avoid disparaging the Dalish.
As for the Dalish being pretty uniform in their beliefs - that's what we see in-game. Especially about the stuff they're self righteous about. The Ferledans and Orlesians are different... but their Chantry isn't.