Why is investing in bitcoin be considered a fraud and if any one claim these they know anything about bitcoin.

If you think that their opinions are right then why you cannot justify that statement  .

You cannot do anything for people who think like that and it simply because they are not interested in understanding the facts and hence there is no point is making them understand anything.

It will be hard for us to convince people who are close-minded to believe in the positive effects and advantages of blockchain technology. We can't blame them since there are lots of people who are using crypto to scam and spread fraudulence. Let crypto speak for itself since it has proven a lot and has passed all the tests of time. Those people who are still doubting about it will realize that crypto isn't a scam when they witness the capability of the blockchain technology to change the economic situation of each country.

i have never seen anybody say that genuinly. people who say it are either FUDsters trying to manipulate the minds of newbies for their own benefits or are newbies who are repeating something they have heard by the brainwashers.
in some cases when they say it they are targeting the altcoins which makes sense as a lot of them are indeed scams created for fast money grabs from the newbies who don't know much.

We could NOT please all people in this world and people will always have different ideas, opinions and thoughts on something, and Bitcoin is no exemption. As a popular cryptocurrency, Bitcoin seems to have become a polarizing object...either you like/love it or you don't. We don't have the responsibility to convince anybody to also like and invest with Bitcoin. Can you just imagine of the maker of Coke will one day forced all people to drink its soda drink? That can be a big controversial move or even an anathema because there are also many people who are die-hard drinking fans of Pepsi. The same thing with Bitcoin. People who are convinced that it is a big scam should be allowed to do so, convincing them otherwise can be a big waste of time. Now, if they can be interested somehow, I am sure they can find a friend in Google.

Explaining to a close-minded person would lead me to nothing. Everything you say to them, they'll just throw you off with arguments in which even if you can explain it, they'll just have another question. Commonly the elderlies who are more inclined into investing to real, liquid assets, are harder to educate regarding bitcoin. Most younger generations are easier to educste since they have the basic knowledge of how the digital world functions and they could grasp the idea and remove trust issues while learning.

A scam is a conscious attempt to deprive people of something valuable (usually, money). When Satoshi created Bitcoin, I don't think that what this person had in mind was robbing people. And I think most people would agree about it. Bitcoin was not even a commercial project or something, not was it an investment opportunity. It was a kind of money people would be able to use without involving intermediaries or supporting certain countries by using their money. If people buy Bitcoin and then sell it when the price goes down and then call it a scam, I think it's their own misunderstanding of what Bitcoin is for and how it works, they should not blame Bitcoin for that.

I'll do nothing, why do we have to make everything clear? I mean why don't they just do their own research? if that's what they think of bitcoin then let them. We don't have to prove anything to anyone besides we have different perspectives, we just need to accept it and understand them since they don't have enough knowledge they'll judge bitcoin anyway so just ignore them. They don't understand that it is not bitcoins fault to be involve in scam situations, people was taking advantage and use it to deceive others because of the benefits they wanted.