first to answer the OP:
a textarea element is an HTML element and there is no way to set the
maximum length of a textarea (you can set max length on a text input
note: max length is not the same as setting rows/columns.
and as far as people getting narky (never heard that word before),
it's most likely because, at least I have noticed, an ever increasing
number of questions that really have nothing to do with Rails (like
this one) or extremely simple questions that could be self-answered if
the poster only took the time to search the documentation or web.
This very same thing was (probably still is) an issue on the php
lists, irc channels and forums as more and more new users began to use
i personally see nothing wrong with pointing people in the right
direction as opposed to providing them with a free answer. a little
push toward self-help goes a long way. call it tough love!