There's no reason for sales to explode to 250M (for a minute there, i thought it was John Lucas making a thread) or even go as high as 150M.
Unlike PS2 or PS4, Switch is not the mass consumer's first choice for a console, nor does it have the best 3d party support to help it reach such a lofty goal.
Not only that but, when 2018 is over, most of Nintendo's biggest IPs will already be out: Zelda 3D, Mario 3D, Mario Kart, Smash, Splatoon, Pokémon (even if not the true core experience). With only Animal Crossing, a true Pokémon (assuming it doesn't share a lot of it's audience with the Let's Go consumers) and a proper 2D Mario (assuming the Wii U port doesn't eat a lot of a proper 2D Mario game audience, when it's released).
We will also have other IPs on the market: Kirby, Mario Tennis, Donkey Kong, Xenoblade, Mario Party and Arms. Leaving Fire Emblem, Yoshi, Luigi's Mansion, Paper Mario, Tomodachi (??), Mario Maker and Mario & Luigi to come out.
So, exactly how is Switch, without the best 3rd party support and only a few system sellers left, going to reach 150m in sales?
Unless Nintendo is sitting on quite a few system sellers that we don't know about and a lot of 3rd party support incoming, it will be impossible for them to reach those numbers.
