Yes, but what is their "rough save" percentage or "closely mown area save" percentage. The bunkers aren't the cause of losing a 1/2 shot, missing the green is!
If we wanted to make bunkers more penal, we'd have to greatly cut back on the number of them. Some courses have hundreds of bunkers, some holes have dozens. I much prefer a hole that has a single bunker that makes you think and affects the play of the hole, whether its a solitary bunker in the middle of the fairway, or one that you have to negotiate in your approach, to holes that overdo it. Some courses have bunkers on both sides of the fairway, because they want to pinch things in at the landing area. Then as people get longer or new tees get built, they add more bunkers to where sometimes you see rows of 2-4 bunkers on each side of the fairway. Then you have a half dozen bunkers practically surrounding the green, to account for people who miss it short in the middle or on either side, plus the pin high misses on either side, and sometimes a bunker in back just for good measure.
I liked Nicklaus' solution of the deep tined rakes, personally.