CNO Tower Controller reported a light sport aircraft engine failure during takeoff roll.

Narrative

Aircraft X engine gave out on the departure end numbers RWY 26R. At this point he is a disabled aircraft on the runway. The pilot still had radio communication and was switched to GC. The pilot informed he could move the aircraft off the runway into the run-up which would allow use of the runway. The OS did not allow it and we had to wait several minutes for an Airport Ops vehicle to come and approve the pilot's request at the site of the disabled aircraft on the runway. The runway was unusable for several minutes when aircraft where already inbound and ILS practice approaches were cancelled with Approach. All aircraft were forced to land and depart on the parallel runway which jammed up GC when taxiing everyone in and really made opening the runway more difficult than it needed to be if we could accommodate the pilot's request when he still had radios. Again; it was only an engine failure and we had full communication with the pilot.Recommendation: Controllers have been receiving conflicting instructions and messages from all members of local management regarding the matter of pilots exiting their aircraft on the movement area for short periods while still in radio communication.Some OS's allow a pilot with radios to exit the aircraft for quick checks it (baggage door check; flat tire check; etc.); some do not. This requires the pilot to remain in the aircraft until an Airport Ops can dispatch a vehicle to 'escort' the pilot around their own plane. What is worse is that Airport Operations leave for the day around XA.30 every day. We do not have much recourse after airport ops are done for the day.We have heresay that the ATM (Air Traffic Management) allows it but due to the conflicting results; the ATM is cutting everyone off at the knees; including the users/pilots. In today's event; the disabled aircraft could have quickly been removed from the runway by the pilot and the pilot's request and allowed operations to continue. From the runway run up; the aircraft can be removed from the runway as it was after the airport operations vehicle arrived.As the disabled aircraft operation wrapped up; the OS explained the restriction is imposed on us by the airport authority due to pedestrian violations. However; there is further heresay this is for flight instructors being left on movement areas without authorization and/or other random pedestrians without authorization on the taxiways.Either way; this can easily be cleaned up with a Read and Initial via the app so that all controllers and all management are on the same page. If management cannot get an R&I (Read and Initial) out; we should at least receive an explanation as to why the ATM is unable or unwilling to R&I what is a simple and routine procedure at similar facilities throughout the NAS.