I must agree that I find high-waisted pants looking a bit silly if not worn with some kind of jacket and/or vest (or a sweater) - especially in my case, as I have quite long legs and the whole effect is somewhat spidery.
It's a problem I grapple with a bit since I prefer to remove my jacket when I lecture; if it's cold, I'm usually wearing a sweater or sweater-vest, so it's not an issue, but when it's warm it can be a challenge to get the proportions right.
My "fix" nowadays is to wear pretty slim-fitting, correctly-waisted trousers (mainly Zanella "Todds") with a pretty trim-fitting shirt (so there's no "mushrooming" at the waist") which doesn't contrast "too" much with the trousers. I'm pretty long and thin (6'1", 158lbs) so it's a challenge to not appear, as I say, spidery (or like some character from a Tim Burton animation

)
The advantage of pairing high waisted pants with a sportcoat OR medium-rise pants with a shirt is that both of those offer 50/50 proportions between upper and lower body - high-waisted (or let's call it "correct" waisted) trousers with a shirt will be more like a 60/40 proportion between lower/upper body... which CAN look odd.
DH