And the fact that they can't afford it gives them justification for stealing it? Would it not make more sense, that if you can't afford something you aren't entitled to it? If a poor or homeless person were to steal food from a shop they wouldn't be allowed to do it because, although they would like to pay, it isn't possible for them to do so.
Is it wrong for the homeless to sleep in your house in the room no one is currently using?
The restaurants have to pay to replace food the homeless would pick up during the day (or even put in work to prepare it for a restaurant). Food that's leftover at the end of the day and can't be sold the next day could certainly be given to the homeless for free (and I know of at least a few restaurants in my city that do this).
The homeless person sleeping in the spare room creates cleanup work, and prevents you from using that room at a moment's notice. If a homeless person could sleep in my spare room without using the shared spaces and leaving the room instantly, in perfect order, the moment I wanted to use the room, I don't think I can morally justify not letting them.
So while the situations you mention may or may not be moral, it's shifting the debate back into a worldview centred around scarcity.
You're committing an act of classism. Please check your rich whiteboy privilege.
But, are crimes in general justifiable if the person committing them does it for self-betterment?
Yeah, probably in many cases. Possibly in this case. But I also worry that it becomes a rallying point for piracy in general. That's what concerns me. I don't think most people pirate media for self-betterment. They do so because they don't want to pay.
To beat on your poor car analogy some more: if copying cars was free and easy, then we would indeed have a lot more cars, but they'd all be 1930s VW Bugs. Competition drives innovation, but there has to be something to compete for, like our dollars.
To your last point: the top torrents at TPB are all video games, TV shows, and movies. Seems more like self-worserment, yuk yuk.
Also, stealing a car is nothing like copyright infringement. There is absolutely no parallel you can draw there.