Yes. It was pivotal in the sense that the snub cemented the idea that the Playoff was only going to be available to the Blue Blood Programs, and nobody else. The Playoff is a ratings/money game, and nothing else. They will put in the teams they feel will maximize their ratings, among the few that reach the level of consideration.
They didn't pick us because we aren't THE OHIO STATE UNIVERSITY, a relentlessly pimped Blue Blood Program. All of that "eye test" "most deserving" "best available" and other ESPNspeak twaddle is just that: Ohio State was picked because they are Ohio State. They have nationwide name recognition, and would (in theory) pull in more casual viewers than an unknown small school from Dallas.*
The impact falls mainly in the recruiting sphere, IMHO. I would imagine that kids hear "You'll never get a shot if you go there. They'll never let them in." Whereas, if they sign with UT, tOSU, OU, LSU, (insert Blue Blood Program name HERE)... I would also think that the continuing bashing of the BIGXII as a whole by the ESPN conglomerate affects recruiting, in that SEC and B1G have the perception of better Playoff chances.
*That's sarcasm. Duh.