I don't see MVP as necessarily what you launch with, but what you need to test with to prove market viability and reduce risk when spending more money/time.
If you seek the literature where the term "MVP" comes from, you'll see 1) MVP is not the same as prototype (you can validate an idea on the market without even a prototype), and 2) there's no definition of "too long", it's situational.
> As I talked about in a previous interview, IMVU’s original MVP took us six months to bring to market. That was a pretty big improvement over a previous company, where we spent almost five years before launching. Yet in another situation we spent two weeks building a particular feature that absolutely nobody wanted. In retrospect, two weeks was way too long. We could have found out that nobody wanted the product a lot sooner. At a minimum, a simple AdWords smoke test would have revealed how utterly bad the concept was. [1]