There are many influential domainers who are uneducated about IDNs and put them down.  Why?  

1. Most influential domainers made their money by buying English .com’s and since that is what worked for them, they narrowly propose sticking to this tried and tested method.  Remember, only recently did influential domainers start to accept ccTLDs and once upon a time English .com’s were considered speculative investments.

2.  From a US-centeric approach it is hard for some  to realize that there are many non-English internet users who type and post in their own language.  The logical progression is that these foreign users will register domains in their own languages as well.

There is risk in IDNs.  Mainly in not knowing what IDN extensions could become the new .com.  But this is a risk worth monitoring, taking, and hedging by regging multiple IDN extensions.