Eth has grown x4000 (From 0,30$ to 1200$). Now, in order for the ethereum to grow x100, it must cost 13000$ - this is too long. There are many other cheap and promising altcoins that are cheap now. And the task is to find such altcoins.
I agree with you, it's quite hard for Ethereum to grow like x100, even x10 will need so much time (new all time high), altcoins are having bigger potential for it. I will choose Ripple (XRP) to be that potential altcoins, i hold this coin more than 1000+ XRP.