Because they're not "Microsoft"'s mistakes, per se: they're mistakes made
by software developers in general. MS just tripped over them, and now so
are we.
Actually, this one isn't even a mistake: it's an inevitable consequence of
what happens when a stable foundation grows that everything relies on,
when that foundation is then shown to be faulty by design. At least we
*can* rip it out: when biology does the same thing, we get stuck with the
same unfixable faults for hundreds of millions of years...