They are not in the cannon because they were not inspired and never pretended to be.
According to whom?
L
The Holy Spirit.
L: According to whom?
If they were canon, they would have been included 2,000 years ago.
"Prots" come under fire regularly for (which is a false accusation BTW) for claiming to have truth the church didn't have for 1500 years and making stuff up.
And now these writings are suddenly supposed to be canon 2,000 year later?
They weren't considered canon or Scripture at the time of their writing. If someone wants to consider them canon now, the burden of proof is on THEM to demonstrate that they should have been considered canon all along.