The problem is that those who invest in altcoins think 300% is low profit. They aim exaggerated goals such as 1000% and even more, which are promised to be reachable by altcoins developers and shillers. That is when investors lose money, because those goals aren't realistic in most cases.
Is a profit of 300% low? In what way is reality skewed? Even though it doesnt promise crazy profits right away, that doesnt mean its not useful. Bitcoin has proven itself over and over again, while these other coins come and go like the seasons.
Its not about being conservative; its about being sensible. But in this crypto world, reality doesnt sell as well as fantasy, does it?