As people have said, genuine warmth and niceness is appreciated, but this reminds me of a tangential thread from another forum, "are happy people more shallow?" I'd say no except for those ebullient, overly optimistic people who bounce through life living in a bubble, willing to sweep under the rug the harsh realities of suffering and other serious issues. A willing to discuss such issues or at least acknowledge them makes a connection much more possible in my case. Conversely exclusively mopey, misanthropic, pessimistic tendencies can be shallow too when overindulgence obscures your ability to accept that life is comprised of both light and shade (guilty as charged).
I used to have a Holden Caulfield chip on my shoulder about how phony everyone's positivity was but I'm trying to just let them be now. If later down the track they realise they've been hiding something heavy from themselves, they'll only choose to confront their real selves when they're ready. I hate when positive people make you feel "damaged" too, by saying "don't worry about it, everything will turn out fine" etc. At the same time they probably don't intend to make you feel misunderstood, they're just advising what works for them as we all probably do. I can't blame their level of insight bc they may not have gone through very much or their temperament's defense mechanism is to suppress negativity. At least I can always choose to avoid them.