I wouldn't say the online service overall is "rubbish" (considering its currently free too), I find actual online play is very smooth and have never experienced issues getting online or lag in my 200+ hours online. Its fairly easy to play with friends - as long as you've planned ahead.
Now, if you're just talking about supporting social features then yes it's a bit rubbish right now.
I don't mind paying for it, especially considering the other benefits and how cheap it is.
I'm not mad that they're charging for it or anything.
My feeling is that keeping it free could be better for Nintendo in the long term however, considering their family / 'for everyone' focus too, many younger people will now have that barrier to get online.
It's worth noting that playing PC games online is free, so many developers are able to fund server costs just fine without charging extra. Playing online with Nintendo consoles has been free for many years now (ds, wii, 3ds, wiiu).
It's not a big deal really, I just kinda feel Nintendo could run a successful subscription service without having to charge for online play.