Gordon,
Just to set the record straight a bit. I believe Aldora is owned by two people. One of those people is Dave Dillihay and while Dave is a US citizen formerly living in the US, he has moved to Cozumel full time, purchased a house there and moved his family there including putting his children into local schools. Dave has invested much time, effort and hard earned cash into Aldora and thereby brought far more into Coz than he has ever taken out. The other owner (50% owner I believe) of Aldora is Memo Mendosa who is a local, a Mexican citizen and an excellent divemaster/instructor.
Given the profile of the two owners I don't believe the "gringo owner" reference applies here. Aldora is not an americanized chain like Hooters or Dairy Queen that exports any profits or franchise fees. They exist as a single operation in Cozumel only. From what I understand (from a divemaster they were working with on a trial basis) they are one of the highest paying operators on the island for their divemasters/captains which certainly helps the local economy (at the expense of the owners wallets).
You have stated valid reasons for prefering other dive operators on other posts and Coz certainly has many fine choices along these lines. You are obviously a seasoned Cozumel regular and I'm sure you don't mean to promote any misplaced "gringo owner" biggotry.