It is not wrong if an investor decides to allocate 5-10 percent of his/her income for Bitcoin investment because you do not know how big the income of the investor is, or the 5-10 percent the investor decides to allocate for Bitcoin investment could be what the investor can possibly afford to invest in Bitcoin so that he/she will not go out of the game. Even if Bitcoin isn't a shitcoin, since Bitcoin is a long term investment, it is always advisable and important for investors to accumulate Bitcoin within their discretionary income even if the discretionary income is $10 so they can hold their Bitcoin investment for a long term.
It is quite understandable because investing 5-10% of our discretionary income into bitcoin won't really stress us that much compare to when we are investing an amount that will mount pressure on our finances. If there is slight changes or volatility in the market won't be exposing all our income to risk, and also investing in bitcoin for a longer term and holding until our portfolio is in profit. However, as a low coiner in other for our portfolio to be in good position there maybe need for being aggressive using our discretionary income .
It makes no sense for a bitcoin investor to invest only 5 - 10% of his discretionary income because it's definitely going to take him or her quite a lot of time or years to accumulate something tangible that can impact his financial status.
I know that most people will argue that 5-10% of some investors discretionary income is very huge, yes it might be very huge to some, but to that person, it's just too small because that's his level. The ideal figure we should be talking about is like 50-60% of your discretionary income or more, that way you can be able to acquire a lot of unit of Bitcoin faster than just 5-10% that is just too small to the investor in question base in his level.