I'm not saying you're wrong, but none of those logos is nearly as simple as this one. For example, I wasn't taught a formula for calculating their area in elementary school.
Are there any successful logos that really are this simple?
Interestingly, the red cross logo is actually a trademark of Johnson & Johnson [1], not the Red Cross. It's also easily confused with the Swiss flag, and Swatch Watches (though granted they have inverted colours). Unless there is some context you wouldn't necessarily know which brand that was referring to. If you remove the colour (as is proposed on the page), it's just a plus sign and not recognisable at all.
all of those are significantly more complicated. you really can't argue that a shape made up of one very simple shape is only slightly less complicated than a shape made up of a couple/several simple shapes. by that logic, you could argue that every letter in the Latin alphabet is very simple; I'm sure everyone would agree that there is a significant difference in complexity between a rectangle and an uppercase 'F'.
With the website you are on it is highly likely that many people would instantly recognize the logo. Maybe not the general population, but here, definitely.
Sure. Just weird to include it between Nike and Google as a company big enough to use simple shapes as logos. I didn't recognize it (obviously). Not a bad logo, though.
Target has almost the same logo just with circles and would be a better example.
http://www.owenjonesdesign.com/wp-content/uploads/2011/05/1_...
or this:
http://www.wearesuntravel.com/SquareLogo_Jewel.303162624_std...
or this:
http://www.vintagevideogamer.net/wp-content/uploads/2012/04/...