To be fair, the said app clearly told people what exact data would be collected and how it will be used. If people does want and chose to sell their data, is that still morally corrupt for the company collecting the data?

In my experience large majority of non-tech people do not care much about their data being collected and would be happily accept monetary reward for things like their location history, usage stats etc. Assume that data collector is using this information to show you relevant ad. I wonder why would it be so much bad to see relevant ad then irrelevant ad? It's not that you are going to stop seeing ads anytime soon.

So the question is: If data producer is happy to sell the information and data collector is using it to enhance the user experience (i.e. no evil intent), would you still consider this bad or immoral?