It wasn't "polluted" with shovelware. All the major platforms have shovelware, and I'd actually say Wii U has less of it than other places. It has less of
everything though. Most developers knew it was a bust to release there and avoided it. (PS4 and XB1 publishing policies are both more indie-friendly than Wii U's IMO.)
You don't notice the shovelware so much on PS4 because there's a variety of
good stuff to look at in the store instead. On Wii U there's hardly anything at all on the store, you can't look at a "best of" selection because there isn't enough to make such a thing. It's like, 1st party, then maybe minecraft and shovel knight. It was so spare that
Meme Run ended up on the console's main menu for a month or two because it was the only thing selling on eShop at the time!