Rudeness

I had someone send me a message through Whatsapp. He asked for my opinion on which design to choose for his corporate brochure as well as for my feedback, if any, on the designs available.  

I gave him my choice and provided him some simple feedback. And thereafter there was zero response from him. 

Like wtf? I took my time to help you evaluate and then there was no response? Not even a thank you? How rude can you be? And no, you are obviously not that busy if you have the time to type out a 300-word FB status. 

Why ask me in the first place if you are not keen or sincere enough to respond?