The thing is, the professionals who have dozens of weddings under their belts, having the experience and skill, also say you need back ups, and even better if you have backups to those backups.
There is a site called shotkit that goes through various professionals bags, lenses are varied, though it's normally 2 primes or two zooms at the minimum, many times it is a huge amount of lenses, BUT, always 2 bodies, even if they are shooting with them at the same time, that is technically backing up the work.
IMO anyone who is telling others that they can shoot a wedding on a rebel a kit lens and a flash is defending their own daft choices.
I have done it on just that, unpaid and naïve, I got a few good shots, good enough to get me some paying clients, but as soon as I was getting paid I used the meagre amount I charged, to rent lenses, and then invest in the ones I liked, and then onto a full frame body etc. I imagine that's a familiar story to a lot of people on here.
The gear opens doors that until you are using it, means nothing, but ultimately, it's up to you whether you walk through those doors.
Listen to the professionals, I have yet to see them say they can do it on a rebel with a consumer lens.
You make some great points. And there is nothing better than good quality gear. But I think that an experienced pro could get great results with a Rebel and a kit zoom lens. Better gear = better images (to some degree). But I know that I could get some great usable shots with the low buck combination. In fact once I had a friend get sick and I shot a paying gig for him with an old 20D. I was in between gear changes and didn't have my own rig available. Client was very happy.

