SJ's: I'm pretty sure most that i know don't fit that stereotype
SFPS:I don't know what 'real life experience' you have with SFP's, but I know several who are highly intelligent- and I do believe that some (as with NFPs) go into the sciences. I can also think of a few politicians I admire who might be SFP's.
As for theorists, and 'trying to pretend not to have feeling' some people who do That actually are Dominant introverted feeling types. (introverted feeling his soooo discouraged by U.S culture)
STP's are not steel hearted. No one is truly steel-hearted, only unhealthy people might temporarily seem that way.