I doubt Home Depot has bad hiring practices, just sounds like you all have bad job hunting skills. Why would you only apply to one place when you have bills to pay? That is just moronic. HD gives hours based on the project sales for that week. Poor sales weeks will cause less hours giving out. Home Depot is a home improvement store and their sales are the highest spring through summer, when most people do their projects. If you apply during the winter months when sales are down, you may not be hired because the money is not there.
If managers are only hiring family members you need to report that to corporate, it is a violation of company policy. Bitching on a internet forum does not solve your problems. Apply at multiple places to increase your potentional for getting a job. HD is not required to hire you, the can hire anyone they believe are withing HD's needs.