It's extremely streamer-friendly (i.e. "fun to watch other people play and react to"), which is a big boost to virality, and it got featured by a hugely popular YouTuber (Dunkey) four days after its launch. And it got lucky. It's not an uncommon story.
More than streamer-friendly, it's Reddit- and Twitter-friendly. Any small clip of the game is automatically funny and share-able. The bird's simple design makes it easy for fan artists to make more memes.
This might not seem necessarilty better for the players, but considering how many smaller game studios / creators are on the verge of profitability, this might mean we get to play games we wouldn't otherwise.
Most of the pushback seems to be because everyone is fine with Steam, yet another store seems unnecessary, and it smells a lot like a rich company buying their way into our hearts (exclusives from all that Fortnite money). I think that's why it doesn't sit too well.
It's about on par with or better than what Steam was when it first launched. Steam was an absolute clusterfuck when it first launched, and Valve only got away with it because they tied Half Life 2 to Steam.
I ended up buying it on Switch shortly after its release.
I spent a very fun couple of hours on this game and memed a lot about it with my partner.
It is not going to have the profound emotional impact that e.g. Outer Wilds had on me but that goose animation and sound designs are perfect and make for good memes that I will also remember.