Scathing review.
A few mentionables:
I do find the tip sheet to be quite rude. I have never seen that before, or perhaps never noticed.
Diving Paradise 3 times is quite sucky, a little lazy.
Their website talks about their "beach" a few times. Calling it so is a bit of a stretch.
No mention of the extra fee for the C-53 on their website either.
The 7:00am breakfast before an 8:30am departure seems ample. Not sure why you were on the pier at 7:50, and personally, I like lunch pretty quickly after returning from diving, so an hour or so there seems ok to me.
The rides to the sites can be long with many dive ops on Cozumel - the waters are often very rough, and 60 min is not uncommon to get to Palancar or thereabouts from that part of the island. Too bad that you were on what sounds like exceptionally poor boats.
I had heard some good things about SCC, although I have never used them.
Sorry to hear that your expectations were not met, and thanks for the review.
PS: Curious to know what other dive destinations you have been to, for the sake of comparison.