Yes and they should be made by former Sega sports developers. In addition, Nintendo should develop realistic sports games without Mario.

I would love to play realistic simulations of sports games. I am not going to buy an extra console just to do so. So, yes, I would love for Nintendo to develop their own sports games. But like many have already said here, I would like it to be in the vein of Ken Griffey Jr's baseball on the N64. Not a Mario themed game.

Yes and no.
They should make some sports games, but they should use Miis instead.

Oh man, what a great game. I would love something like this.

Without the major licenses for the teams and the players from NFL, FIFA and MLB, even a Mario sports game won't do much nor draw the crowds that like those games.

There are options such as going complete fictional leagues but it still wouldn't be the same as every American football game released after EA and NFL signed their exclusivity deal found out the hard way.

I wonder if Nintendo could get a license from the NFL.  They could argue that since EA isn't making the game on their console, someone else should be allowed to have the rights.

This is probably all academic though.  I doubt anyone would even try.

I think the market for games like Ken Griffey Jr. MLB and Kobe Bryant NBA left Nintendo a while ago unfortunately.

So there isn't much point to going that route.

Perhaps they could do Mario NFL Football and let EA co-publish it (since they have the NFL license). That might be an OK play. Mario FIFA could work too.

Neither of these would be game changers or anything but they'd probably sell a decent 800k-2 million WW.

No. They should do proper sports games again. New NHL Stanley Cup, NBA Courtside, MLB Slugfest, NCAA Play Action Football, etc. One title per sport per generation, update the rosters annually, patch gameplay tweaks and add new modes over time.

Why mario sports? why not just a Sports game like Sony's MLB?

Do you really think FIFA crowd will buy a wiiu to play Mario football?(the real one not the handegg that is played globally in us)

They cant even get the licenses so what would be the point? They could do Mario football or something thats not gonna get the sports sims crowd or they could do fictional like someone mentioned but lets be real how much would want to play that?