It's the fault of the catering company, they're responsible for employing the staff, they literally just drag anybody who wants the job in, stick them straight in during a busy match day with no training and have them deal with thousands of pissed impatient angry fans within a very short space of time, their staff turnover is ridiculously high and sadly i don't see it changing anytime soon.
There's ample room in south stand level 1 at the back now but i can't see anything being installed there, there's probably some kind of safety procedure in place that insists that area remains clear for emergency exit purposes.