I think what those people generally mean is that they want to give that 50k out of 200k a try at investments, but if it doesn't work out, it's ok. It's like leaving a part of your money to chances and for your learning.

What you can afford is 200k, but what you can afford to invest and what you can afford to lose to investments may not actually be the same thing, not even for the same person. And I also want to believe people don't just throw their money away in gambling sites and altcoins because " they can afford to lose it".