All 3 major gaming companies are horrible in their own ways. Just like both major smartphone platforms. The times we live in…
At the end of the day, I boycott not just from an ethical standpoint, but from the perspective of a customer. Nintendo is a first-party game publisher. They are uniquely litigious toward their own customers and community, and they don't innovate. Money toward Nintendo directly encourages that.
Any sufficiently large company does lots of unethical things, so boycotting the entire company is harder and sends a less clear message economically. But YMMV.