This argument does not make sense at all to me.
I really wish there was some official name we could call these things. But that's not very likely, considering that LEGO seems to be avoiding complicated names.
Generation X seems awfully generic, and suppose a newbie doesn't even realize that there ever was a previous generation? I know that might not cause too much confusion anyway, but it feels as if there could be some more specific way to distinguish them.
As an example, consider a Transformers wiki. Should they delete everything every other year when a new cartoon comes out to cater to the new audience only? Absolutely not. A wiki is an encyclopedia. It is meant to document everything. So what if somebody whose first cartoon is the upcoming Robots in Disguise show doesn't know there was a cartoon back in 1984. Now they can find that out and learn more about it, should the choose. (As an aside, Generation 1 was a fan term to refer to said '84 show -- and was eventually adopted by Hasbro as an official designation! Because there was none to go by and it worked just fine. Of course, everything since then does have a subtitle and I sure wish that had been done with BIONICLE's resurrection, but alas LEGO opted not to.)
Or My Little Pony with its four generations. Young fans may not know that Friendship is Magic wasn't the first MLP. But they can find out more about the old ones if they want.
Generation 1 and Generation 2 seem perfectly descriptive to me. They are not too specific, but do at the same time clearly convey that there's more than one continuity.