This is unfortunate. As a fan of the series, I'm sad that this only gives Nintendo another excuse to shelf the series for another 10 years.

Metroid prime 4 will sell like it should, series isnt going anywheres.
If anything only lessen will be the market for the 2D metroid is growing smaller and smaller, and Nintendo will stick to makeing 3D versions of Metroid.

I hope you're right about Metroid Prime 4 (Metroid Prime 1 is the best game on the gamecube, easily), but a world without the prospect of 2D Metroids is a world I don't want to live in.

I played it and beat it, and loved it. I'll probably play through it again when I get in another Metroid mood (likely around the time of MP4).

I played and loved Samus Returns, but it did come out at the wrong time on the wrong system. I think Metroid Prime 4 will not have a hard time reaching over a million copies sold though, I just hope it sells more than enough to justify a sequel 

To be honest, I blame Nintendo for releasing the game too late in the 3DS lifespan when all the core Nintendo userbase was looking for the Switch. Plus the game isn't really that much inspired. It's not a terrible metroid like federation force, but it's not a really good one either.

It was an awesome game, but damn was it annoying to play it on the 3DS. I have really grown to hate that circle-pad. Put it Switch Nintendo

Awesome game. They should port it to the Switch.

I mean, like you said, it came out late on 3DS, it’s a remake, and it’s from a series that doesn’t sell all that well.

As long as Nintendo set sales expectations conservatively, I’m sure it did fine.

It is under 1m for the same reason upcoming 3DS games will sell under 1m (Captain Toad, Luigi's Mansion, Kirby Epic Yarn etc), 3DS is dead. Nintendo wants to believe it's not because they don't want to make a 3DS successor now with Switch resembling a console and handheld hybrid. Also, Samus Returns is the second remake of Metroid: Return of Samus. You can't expect gamers to buy every remake like it's a totally new game.

So no, I don't think this is necessarily a bad sign for the Metroid series. We'll have to wait for Metroid Prime 4 numbers. MP4 is a brand new game on a new console with a healthy consumer base, so I expect it to do atleast 3m.