I would imagine that if Steve McQueen knew he would go on to become an icon and start "Wanted: Dead of Alive" the same year this film came out, or be in The Magnificent Seven two years later, he would not have done it. But he did, and we are the richer for it.
Sure it's a camp classic. Horror the way it was meant to be for the drive-in theater. It's fun and nostalgic.
It is interesting that the last lines of the film were:
Lieutenant Dave: At least we've got it stopped. Steve Andrews: Yeah, as long as the Arctic stays cold.
They never would have imagined 52 years ago that the Arctic would be thawing. The Blob will soon return.