I wouldn't buy their games but I wouldn't mind. In fact I'd be happy for the gamers who no longer have to buy two consoles instead of 1. They could spend the hundreds they save on extra games.

And I'd be happy to see Nintendo sell more software then they would otherwise. They might even become mainstream again. Possibly less profit but potentially more, especially in the long run.

I swear this question is asked every week. But yes I would mind. Think about it, them putting console games on other platforms would destroy their ability to sell their handheld games (sans Japan perhaps). Also I don't even want to think about all the potential games that would just not get made if they were shuttled into just being another third party developer.
Couple that one of Nintendo's key strengths being the integration between their hardware and software and it could mean that their games wouldn't be as great as they could have been.

If Nintendo keeps on insisting on a kid-first, second and third approach when it comes to software and marketing, then yes, they should. It's a 3rd party mentality when they should be doing their best to diversify their software offerings -- especially if they're going to continue to make things difficult for 3rd parties in terms of supporting their hardware compared to competitors.

I'd probably be extremely conflicted about it.

I mean, I like buying and owning Nintendo's hardware since it provides a unique experience, and going third party might be inevitable for them one day. I wouldn't mind being able to play Nintendo games on my PC, but at the same time, a certain charm would be lost.

I dunno, not sure if I would really mind, but I would find it awkward, I guess.

Yes, I would. Even as an Xbox fanboy, Nintendo as always been a close 2nd. The only reason I haven't gotten a wii U is because the NX is going to be announced soon. So yes, I would mind...

If they could still make good profit by just being a software developer, I would prefer them going third party.

I would mind that almost as much as I mind seeing people bring this subject up over and over again. Perhaps I'd be less sick of it if discussion of the subject had evolved even slightly since I first saw it talked about around 15 years ago.

In this hypothetical scenario, sure, a lot of the projects and resources for games that wouldn't gain much from the vastly increased userbase of PS/xbox would just be shifted to the 3DS. However they would still stand to gain more by releasing a Mario Kart, a Smash Bros, a 3D Mario and a Zelda on PS/Xbox than shifting those resources to the 3DS (or their next handheld), because their handheld line gets an entry in those series anyways, and most likely whatever game the respective teams create for the handheld wouldn't sell as much as a main entry Mario Kart/Smash/Zelda/Mario on PS/Xbox.

To sum up, basically PS/Xbox would be hypothetically getting entries in the heavy hitters, but a lot of the smaller hitters would be shifted to their handhelds.

EDIT: That's what I think would happen if Nintendo were to ditch home consoles anyway.

No, I wouldn't mind Splatoon on PC

If they are still making consoles, then I would be bothered..