MS is far from being the only ones telling people they need to use something different It's just sensible advice because using an unsupported OS online is a risk, and being WinXP it's an even bigger risk as it's a great fat juicy target with a well developed set of hacking tools to hand and plenty of very experienced WinXP blackhats to use them. It's a fair bet that some very nasty exploits will come to light after April 8th.
I'm a dyed-in-the-wool Linux user and have no association with MS.
As SD says there's Win7 and yes, the Metro interface is a dog on the desktop but add something like ClassicShell and it's quite usable.