I don't think it's inexcusable, its understandable and was intentional. They launched in their first 8 months with BOTW, MK8D, ARMS, Splatoon 2, Mario+Rabbids, Super Mario Odyssey, Xenoblade Chronicles 2, etc. and were still supporting the 3DS with stuff like Fire Emblem, Yoshi, Pokemon, Pikmin, and Metroid.
They could easily have delayed some of those Switch games and had a more balanced release of games into 2018, but I think loading up the system early with games helped make it a success and ensured the long-term future of the console and supporting the full lifecycle of the 3DS was the right thing to do. And ensuring a system's success long term leads to more 3rd party support lately.
Anyway, with SSB, Yoshi, MM2, FE3H, Astral Chain, Zelda LA, Luigi's Mansion 3, Pokemon, etc. within a year I think the drought is over.
With the tremendous Indy support, 1st and 2nd party games, and getting a decent variety of 3rd party games (plus the unique portable feature) like CTR, Crash, Spyro, Doom:E, Marvel UA, Witcher 3, Wolfenstein, MK11......I just don't think the 'not enough games' label that has often been applied to Nintendo is applicable with the Switch.