This is empirically false. A recent look at 39 $1B+ companies founded in the last 10 years: 33% had an MBA founder, to say nothing of the MBAs that have played significant early-stage exec roles (e.g., Facebook's Sandberg, Evernote's Gullicksen)[0]
Amazon also does not appear to be "anti-MBA."[1]
A broader misunderstanding comes from the fact that MBAs are all a particular "type." Top MBA programs are going to have everything from engineers to Peace Core volunteers. Is there any reason to suspect comp. sci. majors who spent 3 years at [insert reputable tech, consulting, banking firm here] and then went to get an MBA are systematically worse for tech jobs than those who did not?
[0] http://bostonvcblog.typepad.com/vc/2013/11/unicorns-and-mbas...