Game has sold however many hundreds of thousands (over a million, even?) copies, and you are doubtful there are thousands out there enjoying it... ok, then. Personally, from my experience of seeing other people talking about it, you guys are in the minority.
And, for the record, you can try it and not like it, that's fine. But personally have a problem with someone who's played the first couple of bouts when it's being introduced, and on the back of that declares it's the worst thing in the game. Sorry, what? It's like watching the opening credits of a film then telling people you think it's the worst film ever made.
Will I play it just as a CCG? Probably not, I lost interest in Hearthstone pretty quickly and I don't have the appetite to keep feeding money into something like that, but in Witcher 3 it's still one of the things I focus on first - running around playing all the shopkeeps, gathering the decks, playing the tournaments etc.
And, if it wasn't popular, do you think they'd have issued real-life versions, trademarked the name and made plans to release it standalone?
My face is tired.