because starting may not be a problem but holding may be a problem, because you are to hold bitcoin for a long period of time 4 to 10 years or more.
what's too complex to learn about holding your Bitcoin? it is not even about learning a thing but just deciding that you are investing for the long term and that's it. unlike trading that if you do a wrong analysis will yield a loss, you don't need all that if you aim to invest in Bitcoin and that is the reason why there is not a lot to learn before getting started in Bitcoin investment. I can bet that a novice can learn about Bitcoin investment in less than an hour and get started but it will take a lot of you are considering any form of trading.
there's not much to learn with bitcoin investment, just learn the basics, get started and the rest is just your ability to manage your emotions so you can stay invested for the long term.
It doesn't take much time for a person to learn and start investing in bitcoin but how to make a profit from investing in it is another matter. That is why not everyone who invests in bitcoin is profitable, many people have made huge profits but many people have lost money because of bitcoin.
I don't think anyone can easily make profit without much knowledge. I don't think anyone would say that they would decide to invest long term and they can easily do that without knowledge.
How can you control your emotions and avoid panicking every time the market fluctuates if you don't have enough faith in bitcoin? And the only way to have faith in bitcoin is to know everything about it, from price history, purpose of bitcoin, use cases...and I don't think anyone can understand all of this in just 1 hour. Not to mention, how can you keep your bitcoins safe if you don't take the time to learn about wallets, security...? There is a lot to learn before investing in bitcoin, and we are investing, not gambling.