I was in Boston one time, and Washington, D.C. another time back in the mid-late-'80s. I recall seeing one or more men wearing business suits with matching short pants. I kind of think it was in Boston, as DC was an out-and-back trip.
Or maybe an Aussie lead guitarist thing. 
I did go for the shorts with suit jacket at a wedding once. In my defence it was a hot summer day and I’d caught public transport there.
I’ve also probably done it once or twice doing grocery shopping while hungover. But that was more so because it seemed funny to me.
What is the point, though? I’ve never worn a suit and thought-- I’m generally OK and comfortable wearing all this business suit crap, but my knees are really hot. I’d go for long pants and short sleeve shirt over that getup any day!
Bermuda shorts are a cultural thing. The suit was adapted to embrace the shorts.
Someone should have thought of inventing the Bermuda Shirt instead. 
At least no one has invented the Bermuda grass skirt.
