Lot of comments here that I skimmed over. I've only been in 1 convertible in my life, and it was an embarrassing car to be in. I'm a car guy.. but there's some cars that I don't want to be associated with.

anyway..

For me, it's simple.

1.. verts weigh more. In the 2014s, it was roughly 130lbs more weight as compared to the coupe.

2.. unless it's designed without a roof in mind (Spyders, roadsters, etc), then you're losing the look if the car. A fastback becomes a brick.
They're fun, but design-wise, the artists behind the car considered the roofline as a part of the car's persona. Take that away, and you lose the stance and fast-looking aerodynamics. You're trading a fast look for a cruising look. It depends on which you want more.

But that's just it. When airflow isn't a focus of a car, then it can look better as a vert. 72 Eldorado, 69 Marquis, etc..