I would say that it was Kimi's cynicism rather than Sergio's over-exuberance that put Perez out of Monaco. Sure, he could have avoided it by not going for the move but then all can avoid a collision by following each other round in a line. Once Perez had committed to the move the only person who could make a decision as to whether there would be a collision or not was Kimi. Kimi chose a collision over relinquishing that position. Sure, Perez him in that position, and good on him for it. That is racing.
"The moment you see a gap and you do not go for it, you re no longer a racing driver". Someone very famous said that once.