It's funny you say, that there was no steam 10 years ago as I own a 12 year membership badge from steam in my steam profile.
And maybe I am a minority of lifetime membership owners here at cheathappens, but therefore I am a german resident, about half of the trainers I downloaded are not working with my game versions. And because this situation would not change, even if I sign a "lifetime membership plus" this is not really an option for me.
I'm sure what they mean is that the steam store was only for valve releases back then. None of this steam store where you can buy other publishers games