Because it's capitalism on steroids? Are you not aware of the world we're living in? Every major forest destroyed, countless species exctinct, climate change reaching point of no return, etc.
We urgently need to slow down, not speed up.
More than that, it's easy to make abstract statements like "we need to slow down", but how do you imagine that could be done? Who decides which sectors need to be frozen and how do we make sure we don't accidentally starve millions of Africans while doing it (look up food self-sufficiency numbers)?
Then, for comparison, research the position people describing themselves as libertarians hold and held on the existence of these laws...
(I'm not a big fan of blanket statements on growth like "we should slow down" either, but libertarians deserve no more credit for the enactment of environmental laws they campaigned against than Stalinists do for the reunification of Germany)