They underbid the time it takes to clean a location, setting you up for failure. The customer is sold a perfectly preformed job, but is told to pay enough for a half finished job where even the most physically fit will have to cut corners just to make a place look presentable by the end of allotted cleaning time.
If working at a remote location they will not deliver restocking of supplies, they will expect you to make the drive to their office and they will not pay you for mileage or drive time.
In general their petty penny pinching hurts their workers.
Management usually will not offer overtime even when they are understaffed, and they are always understaffed.
Their benefits were mediocre at best.
Most of the work is done alone, putting a lot of responsibility on you that you may not be ready for immediately after hire.