McSchool refers to a shit college, that anyone with an IQ above 70 can get into. Often alumni of McSchool find themselves in interviews where the interviewer has to ask where? or is that accredited? Many of these schools are considered prestigous among the elites of academia; but in all practicality the degree is only useful for wiping ones own ass with. (See also any school ending in the word State)
Boss: That Lance kid is one smart bastard, where did he go to school?
Manager: He went to some McSchool down south and played football.
Boss: Poor bastard, in that case the promotion goes to that douchebag from the Ivy League.