One common argument with Switch naysayers is that the third party games it has are already available on more powerful consoles they have. Now, if you don't care about portability, I can understand that argument. The odd part comes in the double standard this has. Because we can apply this to other consoles too. I already played these third party and indie games on PC, why would I buy them on PS4 when I have a more powerful platform? The same argument really.
For Switch, there is an actual reason to buy third party games on it because it lets you play them outside your house. If you don't care about that, fine. But how can you look at 2018, which saw tons of great third party releases and conclude that the Switch doesn't have at least decent third party support?
I Personally consider good third party support to be when a console has a wide variety of good games in various genres for various types of gamers. In that sense, the Switch has gotten off to a decent start. I know the counter argument to this will be "But the Switch isn't getting this, this, and this" Okay, So? It was obvious from day one Switch wouldn't be able to get every single major third party game, especially not this early in its life. But what it is getting is more than enough to satisfy gamers who use it as a secondary system or like its portability, and will only get even better this year, as I'm sure a lot of those games coming in 2019 to the PS4 and Xbox One will get Switch ports. It's better than the Wii U days, where there was practically no third party games that came to the system after launch window.