Definitely part of it. Businesses are afraid developers will come to regard themselves, and to be regarded, as real professionals, like doctors, lawyers, some categories of engineer (god forbid they stop cowering around the MBAs or start questioning the ethics of... well, anything, really!)
Systemically keeping their tastes and station "lower" than that is probably part of what's going on, especially with the bigger companies. Developer pay may (sometimes) approach or match upper-middle, professional-class level, but (self-)respect for developers can't be permitted to reach those heights. Better their conditions are kept closer to, say, mid-20th-century secretary pools.