What do you guys think + or - ?

[Pollux]

That graph is literally showing a slight downward trend, I reckon it probably matches the FL one

It's way too minor to blame the player count decrease to Garry's mod "dying", as if you zoom in a bit more it does seem to be a trend related to it being a weekday. On weekends there is a spike in the amount of people playing Garry's mod, something which isn't being reflected recently in the chart I provided.

Here's the last 30 days for both FL and Garry's Mod:





Note: I think the drops to 0 are the steam updates (where it goes offline once a week), ignore it.

I don't really think there's enough of a correlation here to blame it on Garry's mod.