Well that's the thing isn't it Mark. I can understand venues not wanting to move large cabs around or have them loaded in/out during shows or redoing mic setups or whatever. But saying 'you can't sit your amp here and connect it to the house cab' smacks of complete lack of interest in actual music. What next? You have to use the house Jazz bass*?
*Sorry, was playing 'fantasy pedalboard' and looking at preamp pedal demos last night and they were all done with Js. Okay, that's what it sounds like with a J, all well and good, now what does it sound like with something else?