The issue with the 6 speed Vettes (and really all big American engined cars) is that the gear ratio spreads are massive, even with the ginormous gap between 5th and 6th. That's what happens when you have a car that has enough power to top 200mph and you only have 5 "performance" gears. Giant gaps are kind of a buzzkill in an otherwise fun car.
Now for the vast majority of cars I would not really mind if they only had 6 gears since the first 5 will generally be short enough and close enough. For example my FR-S is a tad above average in terms of acceleration, 1st gear is 3.5, 2nd is 2.1, 5th is 1.0. I find that to be fairly good gear spacing (would prefer a shorter 2nd and 3rd though, the 3-4 shift is totally useless while not on a race track). 6th gear is 0.767, which unless you bolted a turbo to the car or completely stripped the car down to 1 ton curb weight, you'll never reach on the track (5th tops out at 137mph). It would have been better to make the gear 10% taller (engine already runs rich trying to pull up a steeper grade
), and give up a few mph of top speed.
Judging from how I sometimes get 1st and reverse mixed up when I have the lockout ring pulled, I can see why 7 speeds could get awkward. However, I haven't actually tried driving a 7 speed manual before, and maybe I would like it. It's almost a necessity on 300+hp cars.