It's such a weird claim to make especially since the post indicates most adult gamers play casual games on their phones.

Nothing weird here.

For a carefree 13 years old me, it was bordering on personal tragedy loosing 1 to 3 hours a day to damn Quake 3.

I have no words for just how bad it is to be in that state for a person in their thirties, with his/her social obligations and family.

Zynga obsessed adults spending 3-4 hours a day on that are way worse than kids doing the same.

And you add gambling problem on top of that. On mobile you don't even have to input your credit card yourself - Google built a whole freaking gambling/play API specifically for that. One click and it bills your cellphone account, if you live in a right country.