The official CS GO blog has the full statement but here is the summary:
We failed to anticipate the reaction of the community to changes in such heavy-use weapons, and we clearly need to re-evaluate our process for making and communicating about changes in that space. We still think there’s value in trying to find a better balance for pistols and more skillful ways to use rifles, so we hope to tackle rifles and pistols again in the future.
We’re constantly reading community feedback and while we don’t often respond directly, understanding the community is one of the most important parts of working on CS:GO. Mistakes happen, but when they do, we’re committed to making sure they get fixed.
The CS:GO Team