To be fair, the rise of higher criticism from Europe infected the great seminaries like Princeton in the late 1800s, and along comes a system that promised to return to a time of taking the Bible seriously by focusing on a very literal hermeneutic. Men like DL Moody were fighting a battle, and they were desperate for allies. Not excusing them, but it was clear some powerful forces took advantage of that. (Read Machen’s Christianity and Liberalism for a better way to fight that battle).
To this day, a critique of dispensationalism is received as an attack on the veracity of Scripture. And I have friends who are convinced that if you have a consistently literal interpreation of the Bible, you naturally arrive at dispensationalism. That is a tough conversation to have, even if you trust each other.
I think if they would consistently let the New Testament interpret the Old, you naturally reject the dispensational system.