Nintendo has done a lot of courting of indie developers over the last few years, pretty much starting with Shovel Knight, which was the first indie title to recieve an amiibo (little plastic statuettes with NFC chips in them). The “nindies” have been a big part of the push in the Switch and, for the reasons you mentioned, it seems to be going very well. They made a big push to decrease the cost of development kits (I’ve heard quotes as low as $350, vs normally high hundreds if not thousands) and they market them heavily.
It seems to be paying off handsomely for both, with the Switch getting a reputation as the best console for indie games and, when indie developers talk about how their sales go, the Switch is often the biggest platform period or just behind PC. There’s a lot of value in being able to take those little indie games portably.