Why can't Microsoft get their act together?

How many times have you tried to enter something into a Microsoft Office
program and a small window appears with a comment along the lines of "You
can't do that!" - you're puzzled, so you enter a 'key' word, that has
appeared in the small window, as a question in 'Help' and the supposed help
that appears is hopeless !

Try this - (Excel2007 - I'm not a fan !) Enter "History" as a tab name. Up
comes the window 'History is a reserved name'. Ah, I wonder why !

OK try entering that sentence or words from that sentence into the 'Help'
search. Do you get a satisfactory result ? (This is just one of many examples)

So why can't the code writers and the 'help' file authors get their heads
together and produce a help system for words presented by the code writers?

I've had my moan - so can anybody please tell me in what context is
"History" a reserved name when it comes to labelling a tab?