Disney cast members are unionized. The person has to screw up pretty bad to be let go.1) WDW has been trimming the Maintenance staff over the past couple of years.
2) According to my dear friend, in Maint, there are not enough to cover basic even Preventive Maint.
3) This causes major breakdowns, since the equip just gets worn out (sometimes just due to no grease/oil).
4) When emergency repairs pop up, the experienced Maint folks are not available.
5) WDW let go many of the long-term folks since they made so much money (top of pay scale).