I think the general consensus is that if you find something useful, after pirating it, you will pay for it. Pirating removes the need to buy first to see if you really like it or is it something you really want.

I can only speak for myself. I have pirated many softwares and books to see if I find value in it. If I do, I pay for it later. For instance, I recently pirated a book (A Short History of Nearly Everything) and I loved it so much, I bought two copies the same week and gave them out as gifts to people who I am sure never heard of that book or the author and who doesn't like reading books on their computer. I will admit that I pirated "Things" for mac and now that I find myself using it everyday, I paid for a legal key (after using it for few months).

Obviously not everyone does it, but this is how I justify my pirating habit (I am not proud of the fact that I do it).

I think some people don't like pirate bay because they glorify doing what they do instead of trying to spread the ideology or message of pirating.