They are not discouraging newbies from Bitcoin but rather from trading Bitcoin. Say it as it is.

We all know that trading Bitcoin is riskier than just buying and holding, and that's the close warning that some users are trying to pass on to the newbies who think that trading is an easy pizzi thing and also something that they can start doing and relying on it for a steady source of income. I still remember that some months ago a newbie was asking if he or she could resign from his job and start Bitcoin trading, which he felt was going to earn him a huge amount of profit every day, but it's not correct. Someone also ask if they invest like $1000 in trading, can they earn up to $100 or more on a daily basis. There's a possibility that it could be possible, but there's no certainty that they would make such a profit every day. Some days in trading, you might not even earn a profit, and that's what some experienced members here try to warn newbies about. Even I made some mistakes while I was trading, and at a point, I got upset and stopped trading for some weeks, yet I still put myself together and continued.