Since the pedal is several inches above the ground (or it would scrape it), that puts your foot several inches above the ground when your leg is fully extended -- which means you can't put your foot down. If your seat is at the proper height, and you come to a stop and try to put your foot down, you will fall over, and the other bikers will laugh heartily at you.
The guitar isn't going to help you here.
And if you get on the normal way, swinging your leg over the seat with the bike tilted toward you, and then lean upright to get underway, well, a road bike in particular is liable to turn as you get on, because it's sensitive, and you steer by leaning left and right. So you can find yourself turning into traffic, or maybe the curb, which never turns out well.
So how are you supposed to get off and on? Well, you're supposed to straddle the crossbar, then put one foot on one of the pedals, and push the bike forward, picking up your other foot, like you're on a scooter. You're supposed to go from ground to scooter position to sitting on the seat, to get on, and the opposite to get off, which is easy to do with a bit of practice, but who the hell is going to remember an orderly series of steps 1-2-3 when you're about to ride into an obstacle and you hit the brakes?
Not me! I prefer an unexpected crotch full of crossbar apparently.
Wakes you right up.