I first recognized this problem about a year after I discovered the series for myself. To date I still haven't fully reconciled these contradictions. The closest I've come to is this:
The series seems to call us to "take care of [ourselves]," which to me proscribes a balance between indulgence in what makes us happy in an imperfect world full of suffering and engaging with reality. I was talking with an anon about this over a year ago, from whom I got this idea of balance. I don't think Evangelion is totally anti-escapist for this reason, which may excuse us from owning merchandise related to something we enjoy, but it doesn't go along with, as you note, the ridiculous quantity (and quality) of items licensed with the series.
The problem also comes from the series's own outstanding qualities. It is sleek, very tight, and wondrously blends technoreligious symbolism with genuine psychoanalytic inquiry, but in such a way that naturally leads people to think about what it all means (even though Anno himself has said there is no definitive answer, take that as you will). Further, the characters are appealing, not only in terms of the female characters being attractive, but in terms of all of them being relatable and sympathizable, which deepens our attachment to them. So it seems that the characteristics of the series and its characters predisposed it and them to becoming cultural icons and objects of obsession and, indeed, desire for many people.