Nintendo console's popularity is what attracts shovelware. When you have a system that's selling like maple syrup at a pancake festival, every no-name company is going to release some simple $10 game for the system because they're almost guaranteed a profit return. That's why we have such titles as Chicken Shoot and Imagine: Party Babyz on the Wii.
Secondly, Nintendo has consistently proven it's whole philosophic mantra over and over again: The quality of software is far more important than the quality of the hardware. There have been multiple points in history where that type of thinking didn't help them become the industry sales leader, but even at their weakest, Nintendo put out the greatest games ever released.
While most bought the PlayStation back between 1995-2000, the Nintendo 64 had some of the most groundbreaking games ever released, and many that have literally shaped how all modern day games are made (Super Mario 64, The Legend of Zelda: Ocarina of Time, GoldenEye 007, etc.)
In 2001-2006, The GameCube placed a distant third behind the PlayStation 2 with their Grand Theft Auto III and Xbox with their Halo, but the stock of games released for the system was worlds beyond the dark and gritty mature games that were popular at the time (Luigi's Mansion, Super Mario Sunshine, Pikmin, F-Zero GX, Resident Evil, etc.)
And the Wii U, throughout it's lifetime, had the most original and exciting lineup of games while both the PS4 and the XB1 have been keeping afloat with year-by-year multiplatform AAA games that have slowly began to drop in sales (The Wonderful 101, Super Mario 3D World, Splatoon, Donkey Kong Country: Tropical Freeze, etc.)
So why is it that Nintendo is putting out the best games ever released, despite it's hardware not being up to par with it's competitors half the time in one way, shape, form or another?
Perhaps hardware itself doesn't matter, it's how you utilize it.