I will make a point to avoid any of these outfits.I think you miss the whole problem with boats. Perticularly the ones that deal with vacation divers. Many boats provide services to the vacationer croud and as such they limit what the divers can do. Drop below 100 ft and you are grounded for the next dive, no doubles, no DPV's no DS's no deco, dive with in your limts of rec warm water single tank diving. Now if you get hooked up with a more professional operation that historically deals with more experienced divers then the limits are much more relaxed if present at all. My flower garden trips was no nitrox no DPV's no dry suits. A recent carribean trip the op was concerned of our use of a BPW's. Well actually death traps as they put it. If I were out of FLA It would not be nearly as big of deal as the local gulf ops are. I am absolutely sure that restrictions are geographically defined. Its hard to justify an unknown diver that presents an OW card renting gear in 80-90f water that they should be in a dry suit.
Do they check all dive computers for transgressions such as going to 101ft or being 1 min over NDL?
Do they restrict the use of small recreational doubles (where the gas volume is often the same or less than a 15L)?
By forcing divers to only wear wetsuits or no suits, are they willing to face the consequences of an "unwarranted" DCS hit where the diver was within NDL but was more susceptible to DCS due to cold (cold has been proven to be a major factor in DCS)? Just because we term it warm water doesn't mean we all feel the same in it. Warm to me is anything remotely near 20C but to someone used to hotter climates that would feel chilly.
It should be up to the diver to decide on the best gas for the dive - if someone wants to use nitrox and is trained to do so, why should they have an issue?