Valve has pioneered the free to play model with their game Dota 2. The game publisher had a runaway success with the business model and as a result a few years ago, we saw an impulse to make CSGO F2p as well. However, Valve stopped short in its tracks, mainly due to the problem of hacking and cheaters using smurfs and alternate accounts.
However, with the recent advancements in their anti-cheat definitely might suggest that Valve will be looking to make the game free to play. While the number of cheaters and hackers has definitely come down in the game, it does not totally eliminate itself from the game.