Just comfort with water on their face? THAT is wrong. Good diving doesn't come from getting in the safety of a bathtub and splashing water on your face. It comes from being in the water and enjoying it and being the master of yourself in the water. Sure, you dont necessarily need to be a marathon swimmer now, but the experience of being that comfortable shapes the way you approach the water and activities within it.
Being wary and uncomfortable in the water is a huge stumbling block to training great divers and is the reason so much damn time is spent on mask removal drills instead of diving. If you have to ask "do you need to be a good swimmer to be a diver?" you shouldnt be a diver yet, because people who are comfortable enough in the water to be a competent diver never have that question cross their mind. Just my opinion.
What you're saying may be your reality, but it isn't everyones.
I've already stated that I am not a great swimmer, but I have great trust in my equipment and an understanding of how it works. My wife, on the other hand, is a great swimmer, was a lifeguard as a teenager, and hasn't been able to get past the claustrophobic feeling she gets being on the regulator.
By the way, I'm kind of afraid of hights too, but have no issues rappelling down cliffs or operating a tower ladder. Again, it comes down to training with the equipment and having faith in it working, and understanding it well enough to troubleshoot when it doesn't.