Bitcoin is the best because those who are smart investors must invest in Bitcoin. And investors who are ready to invest for a short period of time and are prepared to lose money will prefer unique coins. But the risk is very less when investing in Bitcoin, that's why people are more inclined towards Bitcoin investment. Because investing in Bitcoin must be a long-term investment because only Bitcoin can help economically in the future.
Wether investment is for the short term or long time, Bitcoin investment should be the goal and not any compromise. No investor invest with the sole purpose of losing money, sometimes it could be that they lack the right knowledge and understanding about Bitcoin and possible consequences that their actions will result to. It could be that those who do this are people who were recently introduced into crypto currency trading and investment without proper guidance or adequate knowledge. Some people just want to dive into something because they heard that it's profitable without knowing the underlying risks.
I actually agree with @Popkon6 that Bitcoin is the best asset for investment with the right approach being long term. People start investment through different motivations with the common denominator being to make money at the end. Like you rightly said, the sole reason for investing is to make profits but care must be taken if we must achieve this purpose and also be able to sustain the money.
You said something about knowledge of Bitcoin, I think it is only basic knowledge of Bitcoin you need to start already because complete knowledge of Bitcoin is still something that is unfolding. That is why we have Bitcoin devs, they are constantly improving the Bitcoin network to add better security and ease of use. To buttress this, you can see that the Bitcoin network is yet to overcome the ordinal attack that was launched on it using vulnerability some people noticed. This was not seen years ago and is a result of continuous study of the Bitcoin protocol. So the knowledge aspect is not something that should be the decider for investment even though it is important.
What you said is true, there are still part of Bitcoin people don't know, where one stop marks the beginning of others, we never can tell if people get to know about it, this might lead to reluctance by individuals who are ready to invest, in the aspect of bitcoin knowledge before investing in it, the knowledge of Bitcoin is a continuous process, once you have the knowledge of how the system works and the secured wallet to use in storing your Bitcoin at this point, I think that you are good to go, other process of learning follows later once you are fully into the business.
Know doubt every investor wants a profit-oriented business and also want to make money in any investment they are into, but such investor should also know that loss in a business settings is inevitable and there is nothing anyone can do to stop it from happening, that's why it is advisable for one to chose the plan that fits him or her in other to avoid self blame.