It's not our job and it's not right to force our values on others because we think it will make them better people when that's not what they asked for. That said, I think it would be different if a news organization was doing the equivalent, and serving items that confirmed prior ideas. the difference there is that in one case they are asking to be happy, and in the other they are asking to be informed. This does of course assume people actually want to be informed and news isn't just an entertainment medium for the customer as well now...
So even though a user might only say "show me matches between 18-35 years old" the app would apply additional filtering based on the user's supplied attributes in an effort to improve "relevance".
I'm not saying you're wrong, or that this was wrong/right but I did want to clarify what the OP seemed to be saying.
It's like how the public wouldn't really accept that if statistics show that all planes are blown up by people from country X, everyone from country X is thoroughly searched and no one else.
Also note that in case of the dating app, if you assume people like X want to date with people like Y and you don't allow them to match anyone else you, you can never validate/improve your assumptions.