We used to have discussions about this sort of thing all the time back on the Temp (being an underground community where talk of piracy was simple conversation made it an inevitability). I was a major pirate years back, and there were several reasons for this. The first, and probably the most prominent (yet the one I am most shameful of) was because it was easy and free. I was a Middle/High School student withy no income and few forms of pay, piracy was so simple that when I was introduced to it (though I originally didn't know that it was wrong) I was hooked. In recent years I've been trying to recoup by buying games that I still have that are pirated (MH3, PW: Rise from the Ashes, and a slew of digital downloads are crossed off of my "to buy" list. So you could say that it was both due to me having no income and "just because", but from a moral point of view I don't know if either one it really in the blue.
The second reason is something that I'm actually quite happy of the result of. My Wii had been collecting dust and I had few games for it, but when I heard you could hack it for Homebrew (which I didn't know could result in piracy at the time) I did it immediately. I started with self-piracy (games I previously owned), then went on to bigger games. This is really what made me fall in love with the Wii (and later the DS). There are a good number of gems on the Wii (especially for the seventh generation), and they're often overlooked. Heck, I overlooked them, too. However, I wasn't limited by price with piracy, I walked freely in a mall that allowed my to pick anything and leave, and it was because of this that I was able to try out some of the best games I've ever played, including Ace Attorney, 999, Monster Hunter, etc. There were so many good games on the two systems that my 360 and PS3 started being the ones collecting dust, and it really revived the love I had for Nintendo that I had at a younger age.
The third reason makes the moral scale wobble in both directions a little. As I mentioned before, there was self-piracy. This, I'm actually completely okay with, especially since companies are trying to faze out used games and incorporate digital downloads into everything. As I said, at a younger age I had no income, and my parents would only buy games for me if it was my birthday or Christmas or for some report card (they were trying to get me to understand discipline and money management, they stopped buying me games at around age 6). How is a gamer to live without money? Trading in games. That was the only way to do it for me, and I traded in a lot of games I would later regret selling and would sometimes buy them back (probably the game that I sold that I regret the most, to this day, is Persona 4). I've lost a lot of great games that way, so I've decided that I would redownload them. Granted, I always prefer having actual copies, self-piracy has actually been a means that I've been okay with (not that it makes it any more legal), not to say that it's something I endorse, though. I, myself, am really struggling with this one.
Two other reasons are region availability and hacking, the latter of which can, and should, be done with an original copy, but the former requires money, hardware, and credentials I just never had.
My point is, there are tons of reasons people can pirate things. Is it ever good? From a legal standpoint, no, it's not. From a moral standpoint, it's subjective and also depends on the purpose for most people. I don't endorse the act but I can't exactly turn my back to what I started, nor can I actually say that it's always bad.