Could the SE Workplace community please review and vote as to whether this question can be re-opened after I edited it just now?
I feel the first question asked "Why do companies restrict WiFi" is answerable in general. However, I do not feel the existing answer given by @RualStorge is complete. Significant security concerns regards to WiFi (MiTM, evil twin, rogue AP etc.) were not discussed as a likely reason. I work as an IT security professional and believe I can add quite a bit more as to why companies tend to restrict WiFi access.