It's a reflection of the changing marketplace, just vote with your wallet. Plenty of other cool stuff with less fiddly filigree to paint.
If gamers want to field a pre-painted army then the vendors are following a demand. I can't see metal dissapearing in the long term but there is always talk of our hobby dying, to be honest most of the stuff we paint (excluding GW) are produced by tiny little cottage industries who are catering to a small devoted customer base.
I think the concern has to be over bringing new blood into 'THE HOBBY', if the pre-paints gets more people into gaming and eventually painting then it has to be a good thing doesn't it? Do you see younger people buying AT-43 and all the other current lines out there? I'd imagine some of us got into this hobby via board games and badly painted D&D minis, is this really that different?