there are ~250 pro installers for OPT that are able to sell enough coating to stay on the list. that number is less than it was prior to the quotas being put in place. and there were obviously installers who left for their own reasons, political or otherwise, such as the couple you spoke with.
so yes, the installer list is smaller nowadays.
thankfully you don't have to worry about OPT since you don't like it, there is apparently little demand for it in your area and you sell a coating that sells itself. but, are you a CQF installer? if you aren't, by offering OPT and being on a pro installer list, you might be capturing a user base that isn't able to have their needs met in your area, as small as it may be. many OPT pros offer other coatings, as you know. i give them props for being able to manage both successfully.