Why to use linux is so hard?

First of all, I'm not a top linux guy and I don't know all these terminal commands, but from time to time I'm using Ubuntu just for learning new things and trying to practice some programming languages in .nix environment. I've a few years of exp in using linux in this way. But each time when I've installed Ubuntu I had different problems, first time it was crashed when I changed permissions to folder where Apache is located, second time something went wrong with fonts and a few times some different problems. But as I listened, linux is a very secure system in all ways, but what is this, when I can crash system just by executing a few commands? Anyway, recently I installed rails in my Ubuntu 11.04 VM, I wrote some post about that experience, and now same thing, after doing something with rails I accidentally did something wrong and my MV crashed, again! Ok, never mind, I copied this VM before these changes and now just replace them, it worked and now I again trying to use my Ubuntu. So, why so many people said that linux is unbreakable OS? I know, all the time I used sudo command that let me to be a root, but I broke it a few times.