I also see many 'verts inexplicably all closed up in fine weather. No doubt everyone has an excuse.
I have my own list of excuses, though I have the top down probably more than many.
1) Too cold. Have to drive a few miles until the heater works before lowering. Unless it's well below freezing, then the top stays up the whole time.
2) Too hot. Around 28C the air con goes on, don't care if it mostly gets blown out, it helps. (Mostly directed to the floor vents helps) At around 33C, it's unbearable, even with air con. Top goes up. Factor in the fact that at 2000m elevation, the sun is VERY intense.
3) Extreme headwind. Just too noisy. I'm thinking nearly 100mph speed differential.
4) Busy urban motorway. Just too noisy, again.
5) Extreme short trip. I almost never park and leave the roof open (mainly because seats get too hot) If I'm just running a mile down the road to run another errand, I may leave it up. I have an irrational fear of wearing out the motor, even though it may be worse to not use it. No way to explain irrational.
6) Very long trip. Not an excuse in itself, but tolerance thresholds above are lowered so that top is usually not down the entire day, it's just a bit too tiring.
Ultimately, still just excuses. But if conditions are too extreme to truly enjoy the top down, then why do it? It's my experience that matters, not yours. Everyone has their own definition of good experience, they do not always match others.