Different distros are good for different people and different things.
If you want to face a challenge, choose Gentoo (or one of many others).
If you just want a system that works and is free, use Ubuntu (or one of many others).
If you are a power user who gets more practical value out of a more customized system, choose Arch Linux (or one of many others).
Having more diversity in distros (which implies having some that are easier to use) can only be a good thing.
Also, you have to remember that Linux itself is not an operating system. Trust me, the Linux kernel has not gotten any easier to use from anyone's perspective.