MMM.... the first text-only game was Adventure (granddaddy of zork), and it appeared in 1972, before DnD, so I dunno about your argument. I think it's very likely that the text-based adventures would have evolved into rogue/nethack, MUDs and graphical RPGs on their own, without the influence of paper based RPGs.
Certainly, they were influenced by the existence of the paper-based games post '74, that is not in question. However, I think they would have evolved on their own.
I'm guessing LARPs would have happened on their own as well. I would think the two of these would have generated a paper based RPG game of some sort.