What do you guys think the security officer should have done differently? His job is to make sure that hotel guests are not bringing unregistered "friends" up to the rooms. This is not usually a gambit to generate revenue; it's to protect the security and safety of all guests. Unregistered visitors to the hotel are more likely to cause problems, drug hotel guests, steal from those guests or from other rooms, etc. It's perfectly reasonable for the hotel to want to identify any visitors entering the hotel late at night.
The security officer didn't say "Hey, she's a hooker!" He simply saw someone entering the hotel late at night who he believed, based on his observations and experience, was not a registered guest. Why he believed that, I don't know. If the OP is an older white male and the wife is a younger Hispanic female, well, that might be part of the reason. At some hotels in some parts of the world, when a white guy returns to the hotel late at night with a young local woman, then she is usually an unregistered "new friend." Or maybe he had seen, or thought the had seen, the OP in the hotel alone before and now was surprised to see him a companion. He got it wrong, but I don't think it's fair to expect them to be 100% accurate when seeing someone who they think is unregistered.
If we agree that hotels can and should restrict guests from bringing unregistered "friends" up to the rooms at night, then how else can they do that except by having security officers stop people who appear to be unregistered when they are going up to the rooms? If the security officers never stopped anyone, for fear of offending the occasional couple, then they'd end up letting a bunch of unregistered hookers, I mean "visitors" up to the rooms.
Simply put, stopping unregistered hookers from going up to the rooms is an important respect of hotel security in Latin America and the only way to do that is to stop couples entering the hotel late at night and verify that they are both registered.