When I'm in a hurry sometimes I do. Very close shaves too.
I need the mirror.
Now that you mention it, that goes for me too.
With my goo and cartridge I used to feel my face for stubble with one hand an follow that hand around with my other hand wielding the razor, all while in the shower. Not quite ready for doing that with a straight.
I have shaved in the shower for the last 30 years.. It's just easier, quicker. Also, I feel like I get everything rinsed off. A feeling that just isn't possible using the sink.
I trim my sideburns and back of neck at the sink/mirror before the shower. Then I don't need a mirror in the shower at all.
As others have mentioned, there is some danger in dropping your gear in the shower. I quit buying the glass bowls that some soap comes in.
Now I buy soap refills and one of the aluminum cans with lid to put it in. Works great for travel as well.
Another drawback is that I've always wanted a scuttle, but there isn't a safe place for it in the shower.
I'll always be a shower shaver.