There are no doubt many people who work in McDonald's who do their job dilligently and with care, so is your argument because of a few bad apples those who do it correctly shouldn't get a decent minimum wage? (But I suspect many companies have some who don't their job as well as they could)
I suspect all companies budget for payroll, but wouldn't that be done an a yearly basis? If comapnies knew from a certain date the minimum wage would be X they would factor that into their account.
I have no doubt that many people working in minimum wage jobs do work I know I did and knew many I worked with worked very hard. Yet, it appears in
my area that many of the fast food employees, but not all, have a limited work ethic. This usually appears to be the younger employees, the high school and young college students, who don't seem to really care about the job.
Yes, companies do a budget on a yearly basis, but the ones I worked at the budget for the year, but each day also has a target sales goal. When I worked at Target, every $1000 over the sales goal for the day allowed the store to add 7 additional hours of payroll for that week, however, the reverse was also true- every $1000 under the sales goal meant the store had to reduce the number of hours by 7.
I'm not saying get rid of a minimum wage, essentially doubling it will not necessarily make things better. Oddly, the US government policy punishes people who try to make a living by working, if they are on federal assistance. My sister worked a slightly more than minimum wage job, which resulted in her losing assistance; her basic out of pocket expenses at that time for childcare so she could work left her with $12 left over to cover food, shelter, utilities, etc.
However, based on the current poverty level as defined by the US government, about 26,000 for a family of four, $15 would move them out of poverty, but would oddly probably cost them more than by qualifying for federal assistance with a lesser salary.