Nobody ever claimed they were doing it "to propagate their own interests." The original tweets say this: "Instead of covering the industry with a business press lens or a consumer lens they started covering it with a very tough investigative lens — highly oppositional at all times and occasionally unfair."
Ok, define "unfair." Yeah, having all your problems pointed out is "unfair," but that's exactly what journalism is about? Speaking truth to power.
There are plenty of outlets whose only coverage of tech is critical. This sounds like the NYT wasn't interested in articles fawning over tech, which happens all the time and are basically just advertisements.