[Joonbug1]

Even if ebooks would cost publishers nothing, the notion that someone is automatically entitled to a free digital copy for owning the printed version of a book doesn't come across completely right to me.
I can understand and empathize, as I also had to "double dip" and purchase the ebook versions of books I already owned the printed versions of. I didn't like doing it, but in the end, my love for the books overcame any resentment toward the publishers and the bottom line is I shelled out the money again.
As many readers have done and continue to do.

Someone already brought up how if a customer who bought a hardcover then requested a paperback version for free, it wouldn't fly, either. But the bigger issue rather than cost is the sense of entitlement to access to all versions of a book in all available formats for purchasing one format, and then to keep (permanently own vs. rent/lease) the work.

The publishing industry isn't at the point yet where they'll feel compelled to take the example of movie companies that package a digital copy of a movie along with the DVD or Blu-Ray - and even in those cases, they still figure in the cost of the extra disc containing the digital copies into the price of the sale anyway, so the customer is still paying for the e-version in the end.

Looking at this from the publishers' view, they might also feel that ebooks are more prone to mass-piracy on a grander scale than what they have previously faced with individual hard copies. You can't really compare a situation of one guy burning a CD and giving his uncle a copy versus someone ripping the same album into MP3s and then posting it to a file-sharing server where thousands if not millions of people can have access to it. Something like that can justifiably give concern to retailers and the artists responsible for the work, and is a factor in why certain big-name authors have resisted their catalog being made available in ebook formats.
Does that stop digital piracy of their work? No, someone could always manually create an unofficial scan of their tomes and then decide to have it not be for their own personal use, but upload it to share with pirates.
Heck, he may even do it because he feels entitled to do it just to "stick it to the man" or whatever excuse they may come up with to justify it. It still doesn't make it right, though.
I guess my point in this long post is that it boils down to customers (and I hope they're customers, and not just free-loaders) who automatically feel entitled to something that they use it as an excuse to justify pirating.
I have a friend who worked in fast-food and he would always complain about how much food they waste. If a customer complained about wanting no pickles and someone put pickles in it, the workers would throw the whole burger away and make a new one. He used that resentment to steal food from Burger King every night he worked there (and no, the establishment did not let their employees take home free food, either. It was even against their policy at the time he was employed there).
This same dude also casually talked about how big record companies deserved to get ripped off because they're so rich and they can take it. That kind of mentality to justify (eventual) stealing or condoning eventual piracy is what worries me.