One should not be aggressive about Bitcoin investment at all
It's not a wrong move to invest aggressively when you can from your discretionary income because investing aggressively will help increase your bitcoin investment in a faster pace than when you have the funds to invest aggressively and you didn't. It's when you invest over aggressively that it becomes a problem since you are investing beyond your discretionary income and that becomes gambling.
For the fact that we all are different people with different mindset and different financial capabilities with different responsibilities (probably different beliefs toward Bitcoin), proves that some investors with a very small responsibilities can chose to buy Bitcoin aggressively from the money on their discretionary income and such investors will not have any challenges at all because they have less responsibility and they are also financially empowered.
However, the issue is not about buying Bitcoin aggressively but based on my perspectives, I think the issue is the inability to control the aggression toward buying Bitcoin. The thing is to
Know Your Limit.
One disadvantage of not buying Bitcoin aggressively when you have the money is that it slows down the accumulation process, and slowing down your accumulation process also delays your goal, and such people will likely miss out good opportunities. I believe this is as a result of being too careful, but truth be told that being too careful most times is not far different from taking higher risk.
Actually, the advantage of buying Bitcoin aggressively when you have the money is that you will achieve your goal early, and you won't start to rush I the future when you have more responsibilities and less money as discretionary income, and lastly you will probably have control.
There's one important thing which some people don't understand about discipline when it comes to Bitcoin investment, and it's also one of the reasons why so many people don't achieve their goal quickly on investment.
The truth is that some investors think discipline is only not to overdo thing but it's far more than that because that will not help them achieve their goal quickly.
Discipline also means that you should use opportunities properly when you see them. But some people don't because they mix it up with overdoing which keeps them in one position for a very long time (as they also want to be more careful, meanwhile being more careful sometimes is same as taking more risks).
But taking advantage of opportunities properly, they need to do them with the money on your discretionary income, and they need to understand what they are doing so that they can also have a clear plans.