Wolfram|Alpha is not a general search engine. The slogan is "Computational knowledge engine".
I typed
solve x^2+5x-8=0
into google.com and it did not give the roots, just a bunch of web sites. wolframalpha.com returned the roots and a plot of the curve.
The examples page you provided a link for has an example,
Notable Computers
get information about a notable computer
Apple II
It says notable computers. Specific ones that history buffs would be the most likely to look for.
It does not know about the mainframe Univac 1100/40, which played a bigger role in my career.