Ahem...could we please stop generalizing women. I take constructive criticism well....so it is not fair to really put all of us chicks in the same category. I work out with my "now" husband (we eloped this weekend!!!) and he has trained me for the last 2 years....without incident.
As for PEOPLE ...... there are some that do things wrong -- but not enough to go say something to, and then there are those who are about to hurt themselves or worse, others. Sometimes they (either male or female) take the help with great spirit....oftentimes others, are @$$holes about it and are embarassed and do not know how to conduct themselves well and react well in a less than comfortable situation.
By and large, these people have more issues than meets the eye and moreover are NOT people that you would want to socialize with anyway.
I also believe it is how you present the help and criticism. I have seen normally at peace people doing a exercise wrong and some know-it-all with attitude approaches the unsuspecting victim with such a superior attitude, I cannot imagine ANYONE who would take it well.
But please guys -- all women are NOT bad, NOT bitches and DO want to learn to do things the right way....and we all do not think we know everything and are always right. Just as it is unfair to say all guys who do gear, suffer from roid rage.