And if you were arrested and jailed for pocketing the 20 dollars cash that had been in the wallet before you reported it to the authorities, would you think that a just punishment? No, no you wouldn't and nor should you.
I sort of equate the casual piracy in the same manner and I AM looking at this from the perspective of the company, not the viewer.
All the people out there who are only going to watch something if it's free are already lost money when it comes to DVD sales. If they can see it in syndication, they will, but if they can't they find another way. The only possible profit these people are worth is if they spread it around by word of mouth to people who actually WILL purchase it. If you arrest them for doing this, you are cutting off a source of advertising thus FURTHER reducing your profits.
Back to the wallet thing. If you lose your wallet and nobody picks it up, you're still out the cash. If someone picks it up but pockets the cash, you've STILL got your driver's lisence and all that junk you keep in there back, you're only out the money you would have lost anyway. If you make it a crime to pick up someone else's wallet, then it's far less likely that anyone will return it if you lose it except for the people that would have just stollen the whole thing anyway. Does that make any sense as to why it's not in the anime company's best intrest to arrest downloaders?