What is so diffiult about critical thinking?

Recently somebody left the following spam on my Facebook FunWall.

Attention all Facebook membeRs.
Facebook is recently becoming very overpopulated,
There have been many members complaining that Facebook
is becoming very slow.Record shows that the reason is
that there are too many non-active Facebook members
And on the other side too many new Facebook members.
We will be sending this messages around to see if the
Members are active or not,If you're active please send
to other users using Copy+Paste to show that you are active
Those who do not send this message within 2 weeks,
The user will be deleted without hesitation to create more space,
If Facebook is still overpopulated we kindly ask for donations but until then send
this message to all your friends and make sure you send
this message to show me that your active and not deleted.

Founder of Facebook
Mark Zuckerberg

How can people fall for such crap? Whatever happened to the skill of critical thinking? This particular hoax, “Overload of Malarkey” has been up on Snopes for ages — the old “Please forward this message to as many people as possible or your Hotmail account will be deleted” hoax, only this time retooled for Facebook. This basic hoax has been around since at least 1999 and he Facebook version since December 2006.

I mean, I know most people have little or no understanding as to how computers and the Internet actually work, but are people really that gullible as to think that the founder of such a booming company as Facebook would actually send out a message with such atrocious grammar? Think, people. Think!