I agree, though this does pose a problem for those of us that frequently travel by car. I especially dislike those restrooms that lack paper towels, since I use them as a shield for handling door knobs and such after I wash my hands. I always use a stall and close & latch the door.
On a side note, I once encountered a situation at a rest stop in North Georgia with a guy that tried to run up behind me as I was returning to my car. I'm pretty sure that he wanted to slug me on the back of the head and take my wallet. But, I was very aware of his presence and got in the car in a hurry, one hand on the .38 next to the seat. He came up to the window asking to borrow my cell phone. I just said no and started backing out of the parking spot. I'd have run him down if he tried anything and he knew it. He backed off.
I think it's wise to be very aware in many public situations. It's not just walking in on a couple of gay guys - there's plenty of other potentially dangerous situations that one might encounter as well.
I grab extra toilet paper for that specific purpose. And I use my elbow to push open the bathroom doors.