That's a very interesting point. Gaming is my primary hobby, but I haven't considered that I should buy every big release Wizards makes because of that.It's OK to judge a book by its cover, of course. Nobody would dispute that. I would argue that it's not in our own interests to do so, especially if the book is a major release for one's primary hobby, but people can do what they want.
I tend to buy game books for one (or more) of these reasons:
1. I want to run it.
2. I can glean inspiration from it.
3. I like the art, design, etc.
4. I want to support the writer or developer of the content.
When a product doesn't connect in any of these factors, I usually don't purchase it.
And how many times have we heard criticism on here that we can't review an adventure until we've run it at the table? Are we required also to run something before we have an opinion?