Hete told Ross it was for tax purposes.
Imagine a regular corporation that is comprised of different departments, divisions, or even separate businesses is like a solid bowling ball. If you wanted to break out one of the businesses to sell, you would have to split a bowling ball. You can do it, but it is hard. (The hard part is stripping out revenue, expenses, earnings, liability, depreciation, goodwill, amortization, taxes, value with/without the rest of contributing components, etc. etc)
But why a holding company to buy or sell?
Now image a clear beach ball (holding company) and inside of it you put softballs, baseballs, golf balls and marbles which are the pieces of the old company. Once you go through the accounting hassle of cleaving everything into its own mini-entity, it becomes much easier to add or remove small balls from the clear beach ball.
An over-simplification . . .absolutely. 100% accurate . . .no. But it does give a good mental picture of why and how a holding company was created.
So does a holding company save on taxes, for the most part, not really. 5 pounds of sand in one bucket is the same as 5 pounds of sand in 5 buckets. However, if you were going to sell one of the 1 pound buckets it would give you more control and allow you to artificially inflate or minimize the items listed above, which might save on taxes for either the buyer or seller. (How the debt, income, tax carry-over, and depreciation is divided can make the same sale price very cheap or very expensive.)
So forming a holding company to save on taxes might be a half truth.