Warren Buffett's Berkshire Hathaway (BRK.A -0.28%) (BRK.B -0.68%) lists 56 majority-owned companies in its portfolio. Some are relatively new, like a 2010 acquisition, Lubrizol.

Some, however, have some age. National Indemnity Company has been on the books since 1967. In between these purchases are scores of other companies, acquired over decades spanning from the 1960s to today.

While Buffett may be regarded as the best buy-and-hold investor, he refuses to sell or shut down businesses for reasons other than the bottom line.

Little to do with money
In 1964, Warren Buffett acquired a little-known textile mill by the name of Berkshire Hathaway. The company was reasonably profitable, and it had a growing pile of cash that made its price attractive.

Textiles were a much better business in 1964 than today. Just years after Buffett bought the mills, textile firms began moving overseas. Prices were dropping, and American-produced textiles simply couldn't compete in a world where low-cost international manufacturers could leverage low labor prices to be the low-cost producer.

Berkshire Mills. Source: Marc Belanger

Buffett realized he had a problem. His Massachusetts mills were losing money. But it wasn't until 1985, some 21 years after he acquired the business, that Berkshire Hathaway stopped producing textiles.

On his policy to keep businesses open for as long as possible, Buffett said the following:

"[W]e closed our textile business in the mid-1980's after 20 years of struggling with it, but only because we felt it was doomed to run never-ending operating losses. We have not, however, given thought to selling operations that would command very fancy prices nor have we dumped our laggards, though we focus hard on curing the problems that cause them to lag."

A key component of Warren Buffett's success
Detractors from Buffett's long-term investing style often say Buffett's results aren't repeatable because he gets so-called "sweetheart" deals -- he gets better prices for businesses and higher interest rates than anyone else.

This is true, but it misses the forest through the trees. Buffett doesn't get sweetheart deals because he was born in Omaha, or because his last name is Buffett. He gets them because of his reputation, and his reputation came from his investing.

At the 2009 Berkshire Hathaway shareholders meeting, Buffett was asked if he would consider spinning off any businesses in the company's umbrella. Buffett replied that he would never do that, stating:

"When we buy companies from people, we buy them for keeps. People can trust us to keep our word on this."

Later, in 2013, Buffett offered an analogy for the difficult situation owners face when selling their businesses. They can sell to the highest bidder, who will do anything to make a profit from the purchase, or they can sell to a lower bidder, Berkshire, and know their business will be in good hands.

"You can sell it to Berkshire, and we'll put it in the Metropolitan Museum; it'll have a wing all by itself; it'll be there forever. Or you can sell it to some porn shop operator, and he'll take the painting and he'll make the boobs a little bigger and he'll stick it up in the window, and some other guy will come along in a raincoat, and he'll buy it."

The point is this: Buffett would prefer to lose money, or make very little, from a business he owns than miss out on the next deal. Selling a business, or closing up shop, may make for a rosier earnings report today, but at a very high cost -- Berkshire's future.