Why did sharecropping and tenant farming prove to be unsatisfactory land arrangements?
It reduced African-Americans back to slavery.
Sharecropping and tenant farming were created by white landowners in the South. They desired a method to continue to consistently have laborers, but could not use slaves after the 13th Amendment. Therefore, they created sharecropping and tenant farming.
In sharecropping and tenant farming, former slaves would be employed by white landowners. They would be given housing and sometimes food on the landowners' property, but the landowner would create the terms of the employment. This often entailed a requirement of hours worked each day or similar restrictions. The laborers would work for the landowner constantly.
This system, though good in theory, essentially brought back slavery. African-Americans found themselves once again in the control of white landowners. Though they would be paid for their labor, the landowner would often demand most or all of the workers' pay for room and board, leaving the former slaves with very little. Furthermore, the provided room and board was often the former slave quarters: terrible living conditions for the workers.
Because it essentially reduced African-Americans back to slavery, sharecropping and tenant farming proved to be unsatisfactory arrangements.