Kyuban, as a card, asks for a very particular set of circumstances and feels like a card to be built around rather than slotted.
2 credits is not a bad amount of money to see on a card; Security Testing, Daily Casts, Armitage Codebusting exist on similar numbers.
So why does this little 0 to install beastie not see play everywhere?
Well the problem with a card whose only benefit is to give you credits is that it is, fundamentally, economy. And one thing one wants to avoid is providing your opponent with opportunities to frustrate your economy. Even if the runner goes to the trouble of finding a piece of ice they are happy to pass constantly and placing the Kyuban on it they can only run it a certain number of times before the corp can reinstall.
Therefore it can't be the core part of your economy in the same way that Sure Gamble/Daily Cast/Liberated Account can be.
That said I am starting to find that this card has unexpected high levels of power but it needs to be built around.
The runner has to be able to put pressure on the corp consistently so that the corp can get short of money and time. This requires some aggressive running on the runners part; either being willing to weather a facecheck, avoid a facecheck, or reliably break anything that the runner sees.
The runner also needs to be gaining something more than just the 2 credits on each run; because otherwise why are you not clicking Armitage? Perhaps this could be accesses from centrals, perhaps it is additional run based economy, perhaps you are powering up a Turning Wheel,
The runner also needs to have the spare MU to absorb the MU cost of the card itself.
Personally I enjoy this card a great deal at the moment; it feels like exactly the level of an interesting card at the moment.
I'll await someone building a monster with it and me hating it as with all "whenever cards" .