>but why block Ukraine?

Ukraine is on the one hand a fairly small market, on the other hand a very corrupt totalitarian country, where a huge part of the "donations" will be bribery, money laundering, fraud, buying illegal goods.

So, probably, the company simply decided that it was easier to abandon this market rather than to solve the potential problems.

>moral principle because I didn't want to potentially help launder money to revolting dictatorships.

It is quite applicable to Ukraine as well.

People are literally being grabbed off the street and sent to die in storm troop units. Massive corruption, the main method of protection of which is that those who fight against it (or all their male relatives) are simply sent to die.

But I think it's more about the legal problems created by a small, toxic market than about high moral standards.