And my guess is that you never will see a pro do it in competition. Do they do it while practicing drills? I'm sure some of them have/do.
I don't think the objective is to get straight in. I think it's a great drill, maybe less effective for your typical nine ball players who like the flashiness of going 4 rails around the table.
That same 4 rail highlight reel shot could have been a short follow possibly if the previous leave would have been more precise. As much as you think it's dangerous to get close to straight in, I think it's more dangerous to have to send the cue ball around the table to try to get shape.
Just my $.02
Are you a straight pool player just wondered?