It will certainly be good for marketing purposes for every other portable gaming device, be it PC, Android, Vita, IOS and even Nintendo's own 3DS all of those are completely free online. All of those provide a lot more online games too.
People are comparing it to Xbox live and PSN plus but those are for full home consoles with decent performance and a huge range of online titles. This is only a low power arm based portable with a 150 gflops performance. Any multi-platform titles will be free online for every other portable format.
I think people are being overly optimistic here. Nintendo are first to charge for online for a low performance portable format and there could be some resistance, again not by the Nintendo fanbase so much but the wider audience Nintendo hopes to appeal to as well.
I think again this will be damaging to Nintendo. I just don't think they have enough content to get away with it. Hopefully I'm wrong but I can see Switch failing horrifically in many markets even if it succeeds in some. There are many markets where value is important.
If people resist paying it and then there are few players online then the few who have subscribed will stop and the whole online system gets a reputation for being pointless and people play online gaming on other portables. Without online much of the appeal of Switch games will be reduced and sales will drop. Lets not pretend charging for online is not high risk because it means those that refuse to subscribe have no online functionality and therefore games will be dependent on their offline content completely to those people.
