It doesn't sound weirder than some of the other ideas I have heard!
Let's say that you are a modern Christian and someone is trying to sell you on the idea that Jesus not only did not exist, but is unnecessary for the true Christ is God. Most educated Christians who know their religion and Scripture would dismiss such a thing, while a majority might think it's a cool idea, but it would be a sect outside of mainstream Christianity.
So too with the Jerusalem Jews of 6-68CE. If you told them that the Moshiach was a deity or the son of a deity and if you submit to him you will have eternal life, the concept is so foreign that if you survived the attacks, anyone who accepted it would be outside of Judaism. So Hellenized Jews who accepted the Greek ideas of theology would be a good target.

So too with the Jerusalem Jews of 6-68CE. If you told them that the Moshiach was a deity or the son of a deity and if you submit to him you will have eternal life, the concept is so foreign that if you survived the attacks, anyone who accepted it would be outside of Judaism. So Hellenized Jews who accepted the Greek ideas of theology would be a good target.
“I've done everything the Bible says — even the stuff that contradicts the other stuff!"— Ned Flanders