Disclosure: I'm a mod here, so my opinion is not unbiased.
I can totally feel your pain, and I even don't buy any games on Steam, because they can also be held to ransom, if Valve chooses (or simply screws up).
I totally agree that an offline version should be an option. Shuffle iT promised it, but didn't deliver yet, which I also find unfortunate. There are reasons, one possibly that the level of the AIs is 'not that good' at the moment, also known to the game's creators. There are (most probably) more reasons.
But it also remains true that we, who bought the Making Fun version, knew (or should have known), that we were at the mercy of their servers, and that there were probably licensing deals in the background (as there were), limiting the options Making Fun had. That means while you feel cheated (I know I did when I learned of the end of the Making Fun game), ultimately Shuffle iT is not responsible for that. But I know that that doesn't change the feelings.
But Shuffle iT are responsible for their promises and it is totally in your right to be upset about them, and to consider what you do with your subscription. I probably would have been upset the same if you told me about the current state (no offline version) a year ago. Despite this, I used the 'free year', first played a little, then started helping players with their rules/card/interface problems and now I try to help in testing in general. I like the new game, still think I see the problems, small and big. Some things were definitely better at Making Fun, but would I ever want to go back to playing without the 'undo' option? I don't think so.