Ramsey's influences and biases... all of them... lead him to his philosophy. That's not surprising. I've listened to him a fair amount. While his basic tenet of avoiding debt is a beneficial message for many, his single (narrow)-minded, one-size-fits-all, fanatical approach often leads to some extremely poor financial advice. In my opinion, fanaticism with regard to anything is a negative attribute.
Now, given who is his usual audience, I suspect such advice is likely on target the majority of the time. Still, being completely free of debt is often not a smart financial move at all. Depending upon income, market conditions, investment opportunities, short-term obligations, cash flow, potential future earnings, real-estate conditions, and on and on and on and on, it's sometimes a really good idea to have a mortgage! Sure, you might say that people who are in the financial position where that's the case are not Ramsey's typical auddince. That's true, but he advocates for his position across the board.
Google "Ramsey bad advice" just for starters.
Again, his basic message is fine. Once you get one step beyond that, I'd recommend getting one's financial advice from other credible, objective, balanced sources. I'd never recommend that anyone ever pay Ramsey a nickel for his "program."