Only problem the gamepad ever really caused was its costs in materials to the overall console. But even that is a bad argument. Had WiiU not contained a gamepad and instead had beefier specs, it would still have cost about the same.
Meaning, we'd still have a $300 console that is being sold at a loss with no 3rd party support or sales. It still wouldn't appeal to the MSony crowd that only see Nintendo as a kid company and it wouldn't be in the price range or feature/game aspect to hit the casual group again like Wii.
Making the controller a huge turn off to the vast majority of your prior console owners is still a huge issue even if the cost issue wasnt an issue.
70-$100 would be more than enough to buy 4-6 extra GB of ram. That would do wonders for it's release schedule right there even if it just shared PS4 X1 multiplatform titles. 299 and continued support from the big players like EA(40% of next gen game sales), ATVI, UbiSoft would do rather well. It's substantially lower price would give it reason to have the slightly unequal versions of those games.
I don't really want Nintendo to try to do a spec war with MS and Sony. I'm also happy that you enjoy off tv play so much but when looked at from the perspective of selling the device(which is the most likely perspective given the site) gamepad was a disaster and made it impossible for Nintendo to compete in getting 3rd party software and it made practical applications of their system selling software unappealing.