I cannot comment specifically on this particular fixture, but it's not at all uncommon for manufacturers to put cheapo chinese knockoff lamps into their fixtures.
I think of it like those crappy batteries that come with remote controls when you buy a new DVD player, etc. They don't last long at all. They are really just there as "starter" batteries to get your new piece of equipment up and running, after which you'll buy better batteries that last as they should.
Same with lamps in fixtures. They are there so they can say "lamps included," but the lamps don't often last long, so you should plan on a lamp change with some decent lamps within a short time of getting the new fixture.