Fisherman:
Paul may have deliberately omitted his name in writing to the Hebrews in Judea, since his name had been made an object of hatred by the Jews there. —Acts 21:28
The writer of Hebrews was in Italy and was associated with Timothy. These facts fit Paul. —Heb. 13:23, 24
Haha. I knew in advance that you’d just do a quote grab from the JW “All Scripture” book (page 243). Very bad form not citing your source.
Those aren’t reasons, they are speculation.