While I completely agree with you, I am having trouble finding documentation that this is correct (guess I've been out of the CFI thing too long). As far as my 5 minutes of research went, both the FAR and AIM say that a pilot must receive an ATC clearance before entering Class B. As far as I interpret that, "maintain 5000" or "fly heading 230" would be instructions, not a clearance.

However, would "Cleared direct ABC VOR" work, where ABC VOR is on the field? Would ATC even be able to clear a VFR airplane to a fix or would that necessitate an IFR clearance as far as ATC is concerned?