How come need to get MySQL to work in a strange way?

The following is an error for using RoR with MySQL:

C:\ror\shov17>rake db:migrate
(in C:/ror/shov17)
!!! The bundled mysql.rb driver has been removed from Rails 2.2. Please
the mysql gem and try again: gem install mysql.
rake aborted!
193: %1 is not a valid Win32 application. -

(See full trace by running task with --trace)

C:\ror\shov17>gem update mysql
Updating installed gems
Nothing to update

C:\ror\shov17>gem list mysql

*** LOCAL GEMS ***

mysql (2.8.1 x86-mingw32)


searching the net got this page:

After tearing my hair, installing and reinstalling the MySQL 2.8.1 gem
goggling for answers for an hour I finally found the answer that helped
me. The in the reply from by Hao Zhao, he pointed out that the 2.2.2
version of Rails does not support the MySQL 5.x client!

The solution to this is this:

Download an older version of the MySQL client library from
Copy the downloaded file to c:\Your Ruby install folder\bin

That’s it! I could go mad right now but I’m too happy to finally have
found this.

End of Quote…

How come this is not documented in Rails website or its wiki

I wonder… and it feel a pretty strange way to make something working.