Yeah, I find it odd that it's a science ship myself. The Gorn have been around longer than like all the other powers around them. However they've been almost completely stagnant. Science seems like it would be the opposite of their stagnant culture.
Gorn probably live a long time (assumption based on how they don't seem to like change). They're slow to change. I guess it's possible that they've entered a golden age of progress recently though.
I'd LOVE a Gorn Cruiser some day. They seem like the Cruiser type. Big and slow. :p