1. In Russia, nobody really knows or cares about pussy riot. The western fascination with them is a kind of exoticism. Nadya Tolokonnikova can fill a 1000-5000 seat lecture hall in a major american city, but in Moscow it'd be a surprise if 100 people showed up. This isn't out of fear or anything like that; think what kind of attendance a young, white, American punk woman doing art pranks in America would draw on the American speaking circuit. It's the same in Russia, to most people they're just not that interesting.
2. In Russia, nobody knows or cares about zona.media. This article says "...Media Zone quickly established itself as one of the country’s most reliable sources of information," but it's basically the modern Russian equivalent of IndyMedia: a protest calendar that only a very small contingent of activists pay attention to with the normal levels of radical infighting and articles written for the echo chamber. Nobody "on the street" has even heard of it.
3. Putin has a slight growing problem with young people who didn't experience the "before" and "after" of his taking power in the 90s, but for the most part nobody cares about these stories. If you ask people "on the street" whether they think Putin was responsible for the apartment building bombings referenced here, most will straight up say "even if he was, I don't care, he's still amazing." There was even a podcast (radiolab?) that actually did these interviews.
However, I am very prepared to believe that the Russian state poisoned Pyotr. What I never understand about these recent actions, though, is why? Why go out of your way to poison a no-name activist that operates in fringe circles for researching a story that nobody would care about, even if Putin were to confess live on TV channel 1?