And if I saw the pilot struggling to return to the cockpit, id certainly be helping him kick that door down.
Surely they must have heard multiple people behind that door after a good 6 or so minutes
No, I doubt you would. I'm not sure I would, if I put myself in the position of the average passenger without the benefit of hindsight:
1) I wouldn't want to be mistaken for a terrorist and risk being attack by cabin crew or other passengers, or shot by a sky marshall.
2) If the pilot wanted the help, he would surely have asked.
3) How would I know that he was the pilot anyway, and not a terrorist with a uniform?
4) What reason would I have to believe that this was going to be anything but an embarrassing incident for the pilot, until it was too late?