I don't care at all what people do with their own money. Especially as a business expense, leasing can make sense. And even if it doesn't, it's not my money, so what do I care.
I will point out that in your example above, when you buy the $10K system & Replace it 6 years later, you can sell the old one & recoup some of the original investment. I have no idea how much, but $2K seems about right, making your total cost $8K
With the lease ($230/month * 72 month), you are paying $16,560, and own nothing at the end, meaning that you've paid basically double what you would have paid by purchasing it.