I can see what you mean...to a point.
But just because somebody isn't a real physical specimen doesn't mean they are full of crap. There are tons of guys in the lifing world that look like crap but are brilliant at training others. Likewise, there are tons of guys that look good or lift big numbers that couldn't train anybody with their methods.
Example: Dr Ken Liestner doesn't look much like anything (off the juice) but can train the crap out of people.Stuart McRobert is reclusive, but I'd bet money doen't look all that special. But Stuart's books have helped a ton of guys get started down the right path. Rippetoe never struck me as guy that's went far beyond average strength and build, butpeople pay big bucks for his courses and seminars.