I hate to disagree with you (since I’m on the same side on the bigger issue), but God did give us allegory in Galatians 4:21-31. Fortunately, he was kind enough to label it as such in verse 24: “Which things are an allegory...”
I’m not saying everything written is to be taken with a “hard” literal meaning; Jesus Himself gave us parables, which were allegorical...or even that Jesus is a door made of wood with hinges and a knob! Buck W. was asserting that the historical facts of the Bible were only allegorical. The passage you mention concludes with verse 31—”Then, brothers, we are not children of a slave woman, but of a free woman”, referencing the births of Ishmael and Issac, and how we are now free in Christ. This is common throughout the Scriptures, that is, historic events have allegory attached to them. Those allegories certainly doesn’t mean they aren’t facts, though.
“God did give us allegory”
That was kind of the point... I don’t think any Christian who has spent time in the word is doubting there is some parable or allegory there, but when there is it is usually labeled as such. The Buckster just arbitrarily tags anything he doesn’t believe as allegory.