People have played new games in clearly lesser states on day one. Some people seem to live in a weird bubble where PC gaming does not exist. If you are OK with multiplats looking way better on PC then how will the PS4K be any different? For all you care it's a completely foreign system that does not affect your PS4. There is no proof that PS4 games will start performing like shit the second the PS4K comes out. This is all speculation, however the writing seems to already be on the wall?
Are you happy about how Uncharted 4 looks? This is as good as it will ever look on the PS4. Will it suddenly look like shit to you once the PS4K gets a graphically bumbed up version?
You are ok with multiplats playing better on PC because you dont spend the same amount of thus not getting the same results. When you buy console hardware you buying something you expect to last a generation and not to have an upgrade 2 years later. The poing about PS4 not being affected by the existence of PS4k is true, but only if you believe that devs are going to put the extra time out of nowhere to make the extra dev without any benefits. I think we can establish that PS4k buyers are people who either upgrade or that would buy regular PS4 if PS4k wouldnt exist, thus 0 extra sales.
Performance guessing is speculation, that is true, but it is undeniable how the third party market reacts when there are multiple versions of the same hardware, the lesser one gets the stick. This has been proven countless times during cross-gen periods.