There is the matter of work control--i.e., the company, by virtue of having each remote worker on the payroll, exercises an employer-employee relationship, as o

There is the matter of work control--i.e., the company, by virtue of having each remote worker on the payroll, exercises an employer-employee relationship, as opposed to a client-consultant relationship. However, the company further benefits because the remote workers are/become experts in the software--they are going to know the code better than constantly bringing in contractors--and may see measurable quality improvements by having the same people working consistently on the codebase. I'd imagine companies also appreciate knowing they don't have to worry about conflicting schedules and the like, which can arise with frequency among people who are contracting full-time. And, just maybe, the company actually values the remote workers enough that they want to make sure they keep them around with a good salary, generous time off, and an intrinsic work relationship that shows value to their workers' personal time and needs.