You're an owner of a company and you pay your drivers low wages. Why would you expect anything less then high turnover?
I had dinner with a recruiter for a regional truckload company the other night. Relatively new to the company herself, she expressed surprise at the low turnover at this company and the low wages paid. She said the drivers stay because the company treats them well and keeps them running. For a lot of drivers, it seems, money isn't everything.
Indeed, for many drivers, money isn't anything. They'll happily drive a truck for decades as long as they keep busy. They don't bother to look at the money enough to figure our that they are on a four million mile journey to poverty in their old age and dependency on an increasingly unreliable public dole. As long as they are moving and someone treats them like family, they will happily work for free and pour the most productive years of their lives into funding their employer's vacations and retirements.