"Let's just cut to the chase. They made a choice to financially secure their athletic departments for the next 12 to 15 years," Gundy told ESPN. "People can talk about all the reasons, but that's why they did it, all for the money, and took a lot of history out of this league and a lot of history out of college football with them.
"Now, they're not the first ones to do it. Texas A&M did the same thing when they jumped ship to the SEC [in 2012]."
Gundy, entering his 18th season as Oklahoma State's coach, guided the Cowboys to a 12-win season a year ago and a Fiesta Bowl victory over Notre Dame. Oklahoma State ended the regular season with a 37-33 victory over Oklahoma, which in Gundy's mind will almost certainly be one of the last Bedlam games.
"They sort of made that decision when they left for the SEC," Gundy said. "It's just not going to be feasible. We're scheduled out to 2036, I think, and I'm sure the SEC is going to nine conference games. They'll have to, or the media will kill them. The fans would love to keep playing [Bedlam], but the people behind the doors who make the decisions are going to say, 'No.'
"That's what you lose, some great rivalries and a lot of history."
Gundy is confident that the Big 12 isn't going anywhere and is unfazed about all the talk of the league's teams losing their brand names.
"That's never going to change. They're always going to talk about brands, and there are always going to be teams that get ranked in the preseason polls just because people think they're surely going to be a Top 25 team," Gundy said. "But those polls don't mean anything. Nothing counts until the end of the season, and our brand is growing ... on the field and off the field.
"We don't have the kind of logo that Texas does or Notre Dame does, but we're making strides where it counts."
Oklahoma State, ranked No. 12 in the AP preseason poll, has beaten Texas in eight of their past 12 meetings and has lost only once in Austin since 2008.
"The Big 12 is going to be fine, and I'm just giving you my opinion and know people get upset with my opinion, but we were fortunate that the two teams that left did it when they did [last year] and not now," Gundy said.
Gundy said the four teams set to join the Big 12 -- BYU, Cincinnati, Houston and UCF -- "can compete at any level."
"They have great television markets in different locations in the country that we didn't have," he said. The SEC and Big Ten are going to be strong, but after that, we're right there."
Gundy, never one to shy away from speaking his mind, said he's not sure why he hurt anybody's feelings earlier this year when questioning why OU and Texas representatives were even allowed to attend business meetings.
"I'm just calling it like it is," he said. "If two software companies in the Silicon Valley are battling for leverage through technology, and one of them gets a new technology that could be worth $1 billion in sales, why would they share that with the other companies?
"Now, I said it somewhat jokingly, but I'm not in the administrative meetings. I'm in a meeting with head coaches and athletic directors, and we don't get anything accomplished. We never have because there are too many people in one room. It's a fact. Ultimately the presidents make the decisions. Coaches don't make decisions."
Gundy is one of only six active FBS coaches with more than 30 career wins against AP nationally ranked teams; the others are Nick Saban, Dabo Swinney, Brian Kelly, Kirk Ferentz and Mack Brown. Gundy received a new five-year rollover contract in March worth a total of $33.25 million in the first five years, a deal that includes a $1 million stay bonus if he's still the coach at the end of the calendar year.
It's a contract that Gundy said essentially is a "lifetime deal" and that he has never felt more comfortable with the administration at Oklahoma State, namely president Kayse Shrum and athletic director Chad Weiberg.
"Obviously, OU has been more successful than anybody in this league over the last six or eight years, and we've been second," Gundy said. "So we have a chance with our new administration to continue to push for things, to keep this program at a high level. I've had some other offers, at some really good schools, offers that intrigued me, but I don't think about it anymore. This is home."
The late T. Boone Pickens, the namesake for Oklahoma State's stadium, was the most powerful figure at the university for decades and was "incredibly supportive" with the money he poured into athletics, Gundy said. However, Gundy said it was a challenge at times with Pickens, because he "ran the whole university, and it was not always easy to coach here based on his control from a distance."
Gundy said he interviewed multiple times with Tennessee "because I always felt like that job was a gold mine." He joked that the Vols have had "so many different coaches" that he couldn't remember the specific years he talked to Tennessee.
"That's why I'm so appreciative of what we have at this place, the continuity and stability that we've had," Gundy said. "People don't leave. They stay here, and with our new administration, there's a lot left out there for us."