I get where you're coming from, but the rumors also seem to paint the ps4k not as a console that is going to replace the ps4, but that will cater to the premium market while the regular ps4 will likely release in a slimmer form at a lower price. Basically, Sony is just setting the future in place and releasing it a bit earlier than it would, so that the adopters that buy the ps4k now will be well served for 4 or 5 years and then will be able to pick up a new console for a cheaper cost than they normally would (hopefully, at least). Partially this comes from the way hardware is being produced, as the typical 7-10x jump we get from console generations is likely going to take a very, very long time to achieve at an affordable price. While I understand your concern (as I said, I'm not a fan of this approach either) there is the chance that the original hardware will drop in price much faster than it normally would and pick up even more customers that way. The console market, though not what it once was, is still quite strong.
A lot is going to depend on how Sony sells this thing. If they make it more of a niche for the hardcore, like the Xbox Elite, in order to slowly introduce it to the marketplace while still catering heavily to the regular ps4's massive install base, I think they'll be fine. If they ignore the regular ps4 in favor of the 4k and release poorly optimized software for its already existing customers, then obviously there would be a huge problem there. As for myself, I plan on sticking to the regular PS4, as games like Ratchet & Clank and Uncharted 4 (at least based upon the footage I've seen) are fulfilling my graphics-whore needs quite well and will likely continue to do so for the next few years, at least.