It all depends on your risk tolerance. I like to gamble on lower tier coins every now and then but I only use a small amount of money. looking back at the historical charts you an see how fast some of these coins can move. They can go 100x in a few days which is pretty crazy.
I agree with you man, its all about how much risk can someone handle. With $10k I would buy some bitcoins, I wouldnt miss opportunity to buy iota too (thats from op choices, btc or iota), and some other good coins too. When you look it from other side it would be more risky to invest in just one coin, in some way you are lowering the risk if you invest in more than one coin.
I`m sure that I would diversify, I would split that $10k on more places, on more coins, probably between 3-10 nice investments, in some more in some less.