Trading can be tempting with the promise of quick gains but the volatile nature of bitcoin often leads to significant losses for many investors.
It is not that we are not expected to have raised expectations over making profits from bitcoin, but we only have to know the certain conditions involved in making bitcoin investment and we wont be disappointed with our investment.
You're right that some make losses and it can still be said that many are making profits also in bitcoin, it is expected of every investor to measures on what they can afford to loose, also, we cannot take bitcoin for a get rich quick scheme like the way other investments and ponzi appears, there are procedures and requirements need to go through in knowing the expected decision we must take before investing in bitcoin.
When Kliss mentioned trading alongside with lose I expected something else like trading involving lose but I’m surprised seeing investors, seeing trading as a quick gain is more risky because no one can actually build so fast with trading, investing is always on the safer side or rather if talking about trade and investing, trading should be considered as a risky move mostly beginners. If an investor should hold for 2-4 years or beyond with a discretionary income and with a the proper planning the investor will definitely make profit just like what Dunamisx stated, as an investor you just need to set a target while investing and follow the right path not minding people who never made any profit maybe because they decided to mess everything with a wrong mindset and negative thought.