There are two reasons for the abundancy of ports.
Firstly, the switch is the first console that can provide console-quality games on a handheld system (beside the PS Vita which suffered from its library just being the home console's library but worse so you'd have to buy the same game twice to play it on the go iirc).
Secondly, it has already surpassed the WiiU in sales a year ago:
The WiiU failed due to poor marketing and a gimmick that rarely got good use outside of standout examples like Super Mario Maker. Due to these facts, many people never had a lot of interest in it or didn't realise that it was a new console. Ports give people who missed out on that console's games a chance to play them on the newer, more popular console. And by creating a new market the Switch is drawing in more customers than the WiiU ever could.
Most of the issues you seem to be taking with the system seem to be more targeted at its game library not appealing to you in particular, which is completely fair, but I wouldn't write off an entire system as a knockoff simply because some titles it has don't appeal to you.
For the Switch to be a knockoff of the WiiU, don't you think it would need to also have the gamepad gimmick? I see it more as what the WiiU TRIED to be but couldn't. A continuation of the concept of evolving home entertainment and merging handheld and home console done properly.
None of this is to be taken maliciously against your opinion. See it more as trying to fill in the bigger picture you seem to be overlooking in your anger. As a Nintendo fan it's NOT required of you to purchase every game or console they put out, but you can skip out on games and consoles without getting unreasonably upset over statistical figures or the opinions of other people. Getting upset at these is just childish.