> And if Microsoft makes Windows free and displays Ads to makr revenue they are suddenly an ad instead of tech company?
Insofar as they shift from making the best OS they know how, from how to get the most eyeballs in front of ads, I'd say yes.
It's interesting to compare the reaction to tech companies peddling ads, and this: https://news.ycombinator.com/item?id=18479383 If the ads don't take away from the technology, why in that case do the surrounding ads take away from the words?
Who would you consider more of a cook, someone who makes the best meal they can, or someone who makes an acceptable meal that still makes people thirsty enough so they buy a lot of drinks? At what point does craftsmanship turn into selling out the craft for something else? Who do you think is more of an "actor's actor", or a "comedian's comedian": someone who sometimes compromises on maximizing gain for the love of their craft, or someone who just takes the highest paying gigs, regardless of quality?
So on that sense, sure, they're all tech companies, but so are IBM and Oracle. Just like Adam Sandler is an actor and a comedian. As most fields it's a wide field, it has a high end, a bottom end, and a lot in between.