I've heard this criticism a lot and it always perplexes me, because it's completely divorced from the reality of how mobile ads are bought and sold.

Right now the mobile ad market can work with your approximate age, your gender, your location down to the city level at most, and very high-level interests derived from the site or app you happen to be using at the time. Anything else is too finely grained to sell meaningful volumes of advertising against and therefore not wanted.

I'm guessing people take the reality of the online ad market and falsely assume the mobile market is there as well.