I think Kairon hits the nail on the head. Think about it. Why did people sit and play their 3DS or GBA for long stretches of time? Because there were exclusive Pokemon, Zelda, Mario, DK, etc, games that you had to play right? So you could only get those games on your handheld and thus you would sit in your living room and play those games plugged into the wall like Kairon said, or you would use adapters like the Super Game Boy, Game Boy Player, etc, to play the games on your TV.
SO this battery nonesense goes back to the problem of the way you play. If this machine is the sole Nintendo library and you do not need to pick up the mobile games separate because there is only one library. That is the whole point of the Switch. So those players that bought a 3DS for the exclusives and have to sit and play those games on the handheld, good news you can now just plug it into the TV, see why battery isn't an issue?
Now for the truly mobile gamers, the ones who picked up a GBA, 3DS to actually take it on the go, do you need more than 3-5 hours? Aside from say a really long flight what scenario is there where you would truly be without an option to play this?
Again stop thinking like a 3DS gamer who maybe doesn't own a Wii U or maybe who prefers to sit on the couch and play, those days are over. You can now sit on the coach and play those same games on the Switch, on the TV. I am not sure what the issue is. I mean I am not a mobile gamer so maybe I am going about it all wrong but I always assumed the majority of the mobile gamers were only such because that is where the games were and not because they gamed on the go.
I think that is my best way to hopefully remind those people that might be overreacting. The rest maybe 5 hours is too short I don't know. I just can think of any reason why I would be away from electricity for 5 hours. Even in a power outage I can't see lasting more than 5 hours in most cases. Those rare cases where it might, it's not the end of the world to me.