I've never said otherwise. The B-17G has unlimited use of military power settings which were restricted to 5 minutes in real life, just like every other airplane in this game. The issue as previously stated before was that heavy bombers in-game were able to somehow coax some level of performance from their engines that their opposing fighter/interceptors could not.
I think you confuse terms of what power setting are what sometimes.
There's a max continuous setting, at which most planes can run forever. There's often a higher setting that planes can run for an hour, and then there's military WEP type settings that can't be exceeded for more than a few minutes.
Bombers in AH run at full WEP, whereas the P-51D is limited to 5 minutes of this category of power. The Spit, the F4u, the .... wait... EVERY fighter in this game that even has a WEP setting is limited in its use.
It's NOT the same saying "fighters have the same problem so it's a wash" -- because it's not the same. It is by definition a double standard, and the bombers come out being uber compared to historic numbers almost always in this game.