Why are people so obsessed with some sort of philosophical masturbation about certain keys sounding different from each other; that some keys are more "calm" or "sad" or " jubilant?" This thread seems quite up a similar alley.

Sure, different keys do sound a little different owing almost entirely to the voicings of given chord progressions within that key. The same I chord voiced in a particular way in C might not be able to be voiced the same in the key of F without sounding different just due to tessitura. Likewise, some keys might lay better on some instruments and colors might be different in different ranges, and therefore the same voicing and color issues come up. Also, some instruments just have spots that are idiosyncratic due to things like wolf tones, or pitch tendencies within the harmonic series or what have you.

I suppose to some degree the key might affect a performer, but as a trumpet player I don't care if it's got 5 sharps or 5 flats. My wife (a woodwinds doubler) doesn't care how many sharps or flats something has, even though one or the other might lay a little better on a flute or oboe or sax or clarinet.

I just feel like it sucks that talking about the inherently qualities of keys ends up relying so much on the assumption that the musicians are of a lower tier such that too many flats or sharps freak them out.

There is no better or worse. There's only issues of idiomaticism to given instruments and that's not even a thing as simple as flats or sharps for everyone. It's not always necessarily true that adding more sharps or flats make something harder. In some cases there are just keys that are awkward due to a single mechanical oddity where actually having more sharps or flats would make it simpler.

In the end the question of which is better is like asking if which side of a coin is better... heads or tails? They are just two sides of the same coin and they don't different significantly in any way.