Even assuming that your suspect legal analysis is correct, I can tell you this much for certain:  After pulling a stunt like this, which feels like malware behavior to me, I will not ever buy any product from AutoDesk.

I *was* a potential customer who was trying to uninstall a trial version of NetFabb premium before it expired.  I had decided that this product wasn't what I was looking for, but was still considering other AutoDesk products.  However, when I came across this I instantly decided that I will not be purchasing *any* AutoDesk products -- ever.

Instead of protecting me and their own interests, as you would put it, they drove a potential customer away.  If the common sentiment in this thread is any indicator, I'm not the only one.