When playing a friendly game of TTR in our house it is considered bad form to block unless it is part of your route. Like, it is a completely valid strategy in real life (as it appears to be done in the op's pic) to take the one and two car routes just to be defensive/disruptive. But doing that ruins game night here.
It is fine, but I prefer a more "aggressive" style. I'd love to play one of those games where you pretend not to be the villain, but it would end marriages and result in long stints of not speaking to one another. Sigh. At least we have fun together.