I think you are entitled to your feelings whatever they may be.  It's good that you asked first though.  So many don't.  For me, I would't use something in the beginning if I knew it could not be used commercially no matter how cute or great it is.  But that's me.  I also won't buy a vendor's products if the readme tells me I can't use it commercially.  Most vendor's don't care if you turn their applications into pngs to sell.  However, there are a handful who forbid anyone to make pngs out of their props to sell or give away.  I think it's silly because the people who buy my pngs don't use a 3D program, don't want to, and never will.  They simply want the png to make whatever with it.  They will never buy that vendor's application anyway.  I read and understand the terms and it's my choice if I buy (or download the freebie) or not.  That's why it is so important for me to read what the conditions are before I buy or use something.  I purchased something once without reading the info and found out after the fact, I couldn't use it to sell or give away as a png or psd file.  Now it is sitting in my computer and I doubt I will ever use it.  I learned the expensive way.