I think this prize recognizes her courage and fight for human rights.
Dismissing that as "just being in the opposition" ignores the reality of what it takes to stand up to Maduro's dictatorship.
A dictatorship can be peaceful, and a democracy can be warlike. Venezuela hasn't been involved in any war recently as far as I know. Of course people who fight for democracy deserve being praised and supported, but to me it looks odd to do so with a peace prize.
The prize is supposed to be awarded to people who have "done the most or the best work for fraternity between nations, for the abolition or reduction of standing armies and for the holding and promotion of peace congresses". Is this the case here?
If you walk around all day on metaphorical eggshells, surrounded by armed people who will beat you, torture you, disappear you, kill you and your family if you say the wrong thing, that is not a peaceful existence!