I think Shaul (Paul) is misunderstood and his words twisted, a false version of his writing is the main line teaching making many question his writings.
His writing are THE ONLY writings SINGLED out as being hard to understand, people twist all Scripture but his are the only called hard to understand.
2 TImothy 3:15-16, "And recognize that the longsuffering of Yahweh our Savior is salvation; just as our beloved brother Shaul, in accordance with the wisdom given to him, has written to you, As also in all his letters, speaking in them about these things, in which are some things hard to be understood, which those who are unlearned and unstable twist, as they also do the other Scriptures, to their own destruction."
And when his writings are almost exclusively studied and quoted and Messiah words and the other Scriptures are ignored it is nearly a guarantee to misunderstand and twist Shaul's (Paul's) words.