Never lived in a hot country then I take it ?
Try wearing jeans or dress trousers to work somewhere where the temperature is routinely 25-35C during the day with high humidity and a hot sun beating down on you from a clear blue sky and you might change your opinion.
Even in northern New Zealand where the average summer temperatures were "only" about 24C (with individual days going up to about 28C and on rare occasions into the low 30's) the humidity was often high making any form of long trousers sweaty and uncomfortable to say the least, unless you were working in air conditioning - and no job I ever had at NZ had air conditioning!
In the hottest summer weather I often wore short dress (belt capable) trousers to work - not particularly fashionable to be sure, but necessary! And I wasn't the only one doing it... And if I was wearing jeans to work on a slightly less hot day the very first thing I did after getting home was to get them off to put on some comfortable shorts of some kind, with a great sense of relief. In the peak of summer I'd say half the men you'd pass on the street would be wearing short trousers out of necessity.
I can't even imagine wearing jeans or long trousers routinely somewhere equatorial like Darwin where it is hot and humid all year round...