Most hardcore Nix users/developers I have met have been suspicious for Flakes for several years, so your point rings true.
That said, it feels like they are slowly coming to terms with it and just accepting it as default. Here are two examples of maintainers eventually accepting flake support on their repos after initial hesitation [1][2].
Counter anecdote: all of the hardcore Nix users/developers convinced me it was worth it to switch to Flakes now. They even helped me move my NixOS config as well.
I'm a relative newcomer too— started about two years ago with a Flake-only workflow on Nix 2.3. My sense in observing the debate over this time is that about 20% of the objections are technical in nature, while 80% are around governance— feeling that the feature was smuggled into the main repo as a prototype, despite there being existing external projects (niv) that were trying to accomplish a lot of the same things.