User blog comment:PeterPeter5000/Losing Viewers/@comment-17699152-20140201050449

We've gotta remember that Roblox is being steadily overtaken by games such as Minecraft where the game literally propagates throughout schools. Hell, at the start of High School, kids were playing it in their classes and it took the IT guys to stop them.

Not to mention that Roblox's audience is primarily kids who aren't even teens yet. And because of this we don't have... the best reputation upon others.

Put simply, Roblox just isn't as popular as Minecraft at the moment. Back in those days, Roblox must've been THE thing. Minecraft came along and quickly became a sucess among teenagers because it was touted as revolutionary and new. The kids found out this from the teenagers and wanted to see this "new big thing" and started playing it. They told their friends and soon enough everybody was hearing about.

Now Minecraft is the thing and Roblox's popularity probably died down from these factors.

Still, this is just a hypothesis and I'd probably take Dronian's idea at the moment.