The condos are ocean view and so cheap; there is so much upside. Yes, tax shelter people would be the target, although I myself am somewhat fluent in Spanish and am a frequenter to caribbean hotspots. I think it's less risky than owning a place in, say, Mexico for example, since it's in the US.
Even if they raised property taxes to a punitive 3%, which they wouldn't, I'm not sure how they could tax nonresidents. If they're desperate for capital, they're not going to do things that would ruin that attraction.
Finally, there has been a mass migration to Florida. So there isn't really a population that thinks its being exploited. They are Americans. If they want opportunities, they can just leave.
To me, this is just a once-in-a-while opportunity. PR is the only place you can escape federal capital gains taxes (23.8%) if you are an American, unless you give up your passport.