To take your example of teaching, yes we should try to improve incentives for men to teach.  A number of reasons, one is that many men do want to teach but are afraid of being labelled as paedophiles if they do.  Another very important reason is that evidence shows that boys benefit from having male teachers, and in providing more male role models in their lives.  

So encouraging more men to teach is important both for equality for boys in gaining more from their education through having more male teachers about, and for men who wish to teach in a female dominated profession without facing discrimination (although I'll note that the more senior positions such as school heads/principals are more likely to be occupied by men).

And fashion isn't the best example really because yes you can argue that men may be less interested in it - although reality TV shows I've seen don't really show that to me - but as Fran points out men are still more likely to have the higher paid, higher status jobs in fashion (on the side of design and making garments).  The way that society works, yes, female models are more common and very well paid at the top but how many people reach these heights?  Whereas my day to day work deals with things that impact on the lives of much larger numbers of the working population and not the elite few who make it to the heights of the fashion industry.