It’s largely based on outdated tautology dating anything with a whiff of Gnosticism to the 2nd century which only changed up around the turn of the 21st century.
I’d happily wager with you that attitudes around 2 Timothy’s grouping with 1 Timothy and Titus (which are forgeries) won’t last another 15 years.
P.S. How many of those scholars think there was no historical Jesus?