Could PlayStation 5's power disadvantage hurt SONY?...?

The Playstation 2 was a lot less powerful than the Xbox but it didn't hurt them back then. So why should it hurt them now?

Yes i agree with you. Good question. Less power is the reason i will not be buying the PS5. I saw the graphics. They were wack. I will be buying the Xbox Series X. 

The power difference isn't that huge, but also developers have to scale their games already for the Series S which has less processing power than the X but still plays the same games.

Nope! The people will buy a rock. Remember. This is way better; savvy?

Probably not since the difference between the xbox one x and ps4 pro is bigger then the difference between the ps5 and series x. Also dont expect any games other then microsoft exclusives to be designed specficially first for the series x. The third party developers will design first for either the weakest console, or the console with the most market share, which in both cases is expected to be the ps5. Even if a game was developed around the series x, it should be very easy to scale down the game slightly to run on the ps5s weaker gpu.. 

The power difference is slight compared to say PS4 and Switch, where there have been successfully ported games.

The PS5 may have a reduction in some features, but overall I don't think the slight difference in power will matter in the long run.

It's just a different set of optimizations needed for each system.  This has always been the case.  You never just drop the code for one system into the other's SDK and release it without tweaks.