Russain aircraft a danger at airshows ??

Ok I know this is highly controversial and I do not wanna start a flame war, but after the last crash in the Ukraine and the crashed before (LeBourget, etc.) I wondered if there is connection between these accidents.

1. Are the planes flown above their limits to make a “good” show ?

2. Are the pilots to unexpreinced (or gaining to few actual flying hours) to do such displays ??

3. Are they desperate to make the planes look superior that they cut down on safety procedures ??

4. Are the aircrafts badly maintained ??

5. Is it just bad luck ??

You comments plz.