If you really believe in Bitcoin, then even 50% is too little - although that is the decision of each individual. For some, it may be too much, especially in the time we are in now, because some have a hard time bearing the fact that their investment has lost value and that they cannot know when it will reach the desired value again.
Yep. If you are an experienced investor, 50% is probably not enough. But if it is for newbies, 50% is very very enough, it is even too much as you stated above. At the newbie level, it is better to use a small number of funds. Learning should be the focus, not the potential profits. Only people who have enough experience and knowledge, can consider using 50% of their funds for Bitcoin or altcoins investment. We all believe in Bitcoin future, but sometimes newbies often panic when the price drops drastically. They can fail to take profits if they sell their BTC or altcoins in panic. A newbie needs sufficient experience and knowledge to be a strong holder.