As players what happens is over time we learn the best routes, intercept techniques and targeting. Then start a new career knowing the best places to patrol and armed with the knowledge that a uboat crew had to aquire through trial and error over a couple years. Starting the war having all the techniques mastered kinda feels like shooting fish in a barrel.
Sure racking up tonnage totals can be fun and I have done it provided the visiblity was better than 400 meters

I haven't played past 1940 yet and I don't see the sport in sinking unarmed and unescorted merchants traveling along at 6 knots. There was a time when I was thrilled to hit anything but in the early war things can become old hat rather quickly.
I don't want to date myself but I am a bit older and there comes a time I guess when you just as soon tool along and listen to the gramaphone.