Bitcoin is not a quick and get rich quick scheme, for any one to have benefits from Bitcoin as an investment it will take alot of time with patients and consistence investing, another criticism is that most people always said that Bitcoin will crash some day buti usually let them know that Bitcoin is not a scammed project just like most of other coins, while they will be having negative feeling about Bitcoin others will be taken advantage of Bitcoin, but there is no reason for arguments perhaps Bitcoin is not for everybody and it is not by force for anyone to be convinced about Bitcoin potentials.
You are right, of course investing in Bitcoin is not a way to get rich easily, of course it takes a long process to be able to make a profit on Bitcoin investment and those who think that investing in Bitcoin will make them easily rich, of course there is something wrong with them. understand investing in Bitcoin and it could be that they only see the results that other people have gotten from investing in Bitcoin and they don't see the process they have gone through in investing in Bitcoin until they have made themselves rich.
In this case, of course we don't need to debate whether Bitcoin is good or not and this will really depend on someone who understands Bitcoin and maybe for some people it is not suitable as you said because they don't try to learn it well.