I don't know about the Ukrainian opposition but Putin is pretty evil. And many people who live in countries that used to be a part of the eastern block understand very well why you do not want to find yourself in Kremlin's orbit.
Putin is pretty evil
Because ~65% of Russians voted for Putin, and they did it three times. He is very popular. Not difficult to see why. Since he came to power their GDP per capita (PPP-adjusted) almost doubled, law and order improved, corruption went down. And more Russians are being born than die, so the population decline is reversed.
http://www.forbes.com/sites/markadomanis/2013/02/04/five-myt...
For all his populism, Putin's economic policies have been very shrewd - Russia paid out its foreign debt and has currently some of the largest foreign currency reserves, and one of the lowest tax rates in the world.
As to the efforts to present Putin as some evil thug, throwing journalists to gulags etc. - this is just laughable. The best example are Pussy Riot. When the best anti-Putin propaganda can do is to call a punk-group who insults religious minorities a victim of political prosecution... Well, probably, Russians have to conclude that there are no real issues with freedom of speech in their country!
It's perfectly fine not to like Russians improving their life and enjoying a stronger country. But don't blame poor Putin for that. He is simply an elected official, it's just that Russians have been lucky to find a capable one.
And what is much more troubling - almost every country with powerful ruling class is like that. As people say "паны дерутся, а у хлопцев чубы трещат" (=when those in power, the superiors, are in conflict, it is the common people, the subordinates, who suffer). And curse those Ukrainian officials who let it escalate to this.
There are several power centers in Russia and Putin has to tread carefully with them. There are entire blocks of government that are not doing what they are supposed to do, and forcing them directly is not going to work without upsetting their cover up the food chain.
Just like you said, it is the same in every country with powerful ruling class.
You say you don't know Ukrainian opposition. They are from West of Ukraine. West of Ukraine is notorious for their hatred of Jews and Russians. Hating Jews is not fashionable these days, but there is an open season on Russians. People from West of Ukraine love killing Russians, they don't miss any opportunity, like conflict in Chechnya, where Ukrainians took an active part fighting alongside with Chechens against Russia. West of Ukraine considers East of Ukraine as (1) cattle, (2) slaves and (3) just like Russians but worse. To no surprise, West of Ukraine didn't hesitate to pick up arms and start shooting. They are very passionate bunch. Just watch what will happen when they win (and they will). Central Ukraine will be a blood bath where people will be shot dead for just speaking Russian.
I'm from Poland. I don't know about the current opposition, I'm aware of Ukrainian nationalists and their history[1]. But for the same reason I also fully sympathize with people who do not want to be in the Russian sphere of influence. It's terrible.
Putin is a thug whose regime murders journalists and sends opposition politicians to gulags. As I said, pretty evil. And not hypothetically, perhaps in the future, once he takes over, but really, here and now[2].
Russian empire has always been like that. Behind. And holding back those who were unfortunate to be nearby, too.
[1] https://en.wikipedia.org/wiki/Massacres_of_Poles_in_Volhynia...
[2] https://en.wikipedia.org/wiki/List_of_journalists_killed_in_...