So what is the purpose to use bitcoin if they are already rich and if they have there own business they could use bitcoin to have an extra income if they are really interested. But if you ask me if i am already rich i will be not interested to use bitcoin. I will be more focus in taking care of my own business.

yes you are right  i also have seen in some articles that bill gate have been interested in bitcoin and have large amount of money invest in bitcoin. and some rich people interested in bitcoin but not all rich people have interest in investment in bitcoin the reason behind is that they have less knowledge about bitcoin. or do not want learn about bitcoin

Do you think the richest families or personalities in the world would be interested in using bitcoins??
And if so, would that be a good thing for us small people or negative??
I mean rich people are capabale of so much things, so it makes me wonder..

So many rich people are interested investing there money in bitcoin and we all know that but I guess if they don't have a bitcoin knowledge they will not go on the investment only if they know bitcoin suely they will have and create there own investment surely.

Now my point here is this, rich people who have bad vices or addictions,
Would obviously find it hard to stop what they have been used to be doing
or in some cases, impossible. And let's face it, lots of people are pedophiles,
Necrophiliac, etc. some even love watching live tortures with them giving
the commands on how to do it. And I'd be damned if rich people(specially the
famous ones) that are part of all the people that I have mentioned wouldn't do
everything in their powersto hide their true selves from their family and friends
or other people.

So i think its just fair to not rule out that lots of rich people will be into bitcoins
in the future(for all i know maybe lots of influential people have already been using
bitcoins). But not for the purpose of profit though, but instead, for
the sake of fulfilling their wants and desires anonymously.

Although bitcoin is a fertile land for investment, but for the rich, they have different ways to make money, and they really do not care about bitcoins.

I think they'd care. It's a way of making more money after all. So why wouldn't they?
Probably the only ones who wouldn't are those 2nd-3rd generation rich kids who only knows how to spend. Probably.  
I don't believe that just because someone's rich, they wouldn't care about earning more. As for earning from bitcoin, they could do it themselves or just hire someone to manage it for them. Easy.