At least Luke storming in and yanking Han out would have made sense, as opposed to whatever the hell the plan they executed was. And if it had been a brutal infiltration, with him not just temporarily choking but straight-up slicing and dicing thugs on his way, the Emperor's exhortations for him to embrace the Dark Side might have been even more tempting...Well considering what a huge cliffhanger it was at the end of ESB for Han to be captured and imprisoned in carbonite, and all the questions and theories that had been building up in fans' minds in the intervening years, I can understand why Lucas felt he needed to make his rescue in ROTJ a pretty big and involved process.
After all that, to have Luke simply storm into the palace and yank out Han in the first 15 minutes would have felt seriously anticlimactic, I think.
Although that said, I do 40 minutes is about as long as that section really needed to be. 50 was definitely too long.
Again, though, the big thing is Jabba's main story role in the OT was giving Han a reason not to stick around with the Rebels, what with the bounty on his head and the hunters after him. Once he's killed, he has zero bearing on the actual galactic plot at hand.
The caper to save Han used all the characters acting as team and it gave Luke his first real outing as a Jedi. Han could've paid off Jabba after ANH for that matter, there's real for Han not to have.