I don't think Nintendo don't launch Metroid games because they are mean or vindictive. Companies want money and while I believe Metroid games sell well, they may not well enough.

Personally, I like Metroid more than, say, Zelda but I believe the swordman is more popular. Assuming your team has enough manpower to launch ONE game, which one Nintendo would pick? Even with Zelda out of the picture there is still Mario, Splatoon, Animal Crossing, Brawl...

The Switch presentation was received positively and yet, no Metroid game was showcased or mentioned. I feel Samus is slowly joining the B-team or Nintendo IPs like Ice Climbers and Baloon Fighters.