Yeah you are right, some people feels that accumulating Bitcoin little by little is a waste of time so they feel saving up and buying in a lump sum is the best but one thing is that one can't have money in his or her bank account and be free from little financial problems that will eat up little of that saved money.
Some feels dey can't accumulate Bitcoin again because no matter how they accumulate it will never account to any reason Bitcoin.
People that has this mindset don't know anything about Bitcoin, they don't understand how far Bitcoin will go, now for me I know in the next 10 to 15 years Bitcoin will hit $500k to a million dollar or even more so me starting my accumulation now and continue be consistent will amount to a very good Bitcoin.
So accumulating little by little since one don't have funds for a lump sum is a very good strategy and that strategy can change your life in time to come.
Those who still don't believe in the growth of Bitcoin will regret like those that had opportunity to invest in Bitcoin 10 years ago but refused Because of there mindset.
Some have that mentality that slow and steady is a waste of time, rushing and getting the best result very fast is best to some people. It all depends on how much you have at the moment that's why some don't think it gives something reasonable in the future, Bitcoin on it's own has a way of making the little you have to become something bigger, that's if you have the time to wait.
Those who doesn't believe in Bitcoin growth I see them as those who just started or those who are hearing of Bitcoin for the first time and also doubters too, we have these sets of persons (doubters) who doesn't see Bitcoin as something legit and they have words to use in convincing people not to engage in it and they easily speak ill of what they have no knowledge of.