Yeah, I've seen the posts. I'm sure it's a great dive op and I've stayed at Casa Mexicana. I have no problems with it, or that combination.
My post is in regard the original poster's request. The poster wanted a hotel with shore diving and didn't want to go to the marina via land transport. In those regards, the CM/TP combo doesn't meet either of those requirements.
I took "getting into a car to go to the marina" to mean he didn't want the hassle of finding his own way there. Driving to the marina in a truck takes a fraction of the time and is much smoother than getting there by boat.
He wanted a hotel "close" to the water and CM is close. He wanted to shore dive and it's quite feasible to shore dive as I just stayed at CM last month and did 5 shore dives in 4 days. In some respects, it is preferable as there is a taxi stand right across from the hotel so you can quickly get to any shore dive site. If you stay somewhere like Blue Angel, you have a shore dive on premise but still need a taxi to get to another shore dive site and taxis are not waiting outside the hotel.
Now you may be right in what he had in mind but he may have been thinking you had to be on the water to easily shore dive and that you had to be picked up at a dock to easily get to the marina. We are simply pointing out that it is quite convenient to walk a block (about the distance from your room to dock at Hotel Coz) to TP to be transported to marina, and quite easy to shore dive from CM.