Why do some businesses stay small?

i found this answer on Yahoo!Answers:

Small business generally don't want to venture to hire more workers etc. It makes it more personal I guess, especially if you are an entrepreneur and started your own business. Keeping things under control is also another issue. If the company gets too big the system needs to change. Many small businesses also don't want to sell their products to larger companies. The income is somewhat based on the initial amount you put into your business, so if you keep putting in the same amount, it will never grow

I'm not sure whether it helps,but i hope you can learn/take something from it.

thanks xoxo.