The Witcher - Battle Arena
If they'd only stick to RPGs we wouldn't get a Gwent Standalone. I have no problem with CDPR trying out new stuff, especially when it's about Witcher.
As I see it, the Gwent standalone is right in line with what I would expect from them. The reason for this is that there were people who played TW3 who absolutely could not get enough Gwent in their playthroughs of TW3. Another reason I think its somewhat expected is that there were main quests that give you an optional way of playing this main quest by playing Gwent. And Gwent was done surprisingly well in TW3, which is why Gwent has such a big following. But the real reason why they are making a stand alone Gwent game is because the fans want it - there is a demand for it - so that is why this stand alone is actually going to be a thing.
As far as CDPR trying out a lot of different things, this is a logical move for them. They don't have a ton of different series to go along with TW so they have to use TW as a vehicle to drive things. Its also about diversity and seeing what catches on, which only makes sense. The thing is though, that TW, or rather, TW spin offs really only cater to TW fans who are the die hard fans. TW alone is just a single somewhat niche series, so not everyone is going to love it. On top of this, as TW spin offs get more and more specific, its going to take people who are already TW fans who really like that aspect of TW to get into these specific games. Or just people that are such die hard fans that they would play anything that is even remotely related to TW.
All that said, I really must say I cannot wait until Gwent is actually a thing. A whole game devoted to Gwent sounds like a ton of fun. With a team of people working on this game from CDPR its sure to be done very well, and though it might not be the most popular thing on the market, the people who like it are
really going to like it.