While it "may" be true that editors add value to the authoring process, who says it must be the editor of a publishing company. I've been reading ebooks for more than 10 years now, and I've seen many cases where the author thanks family, friends and/or collaborators for helping with the editing. An author in any genre has a following, many of whom would be more than overjoyed to have an opportunity to preview a book and help critique it to make it better. A small team of fans would be very quick to spot spelling, syntactical, formatting and logic errors, it would cost the author nothing, and she/he can take what advise is given or not, it's up to the author.
I know that human ego, being what it is, makes it very hard to accept criticism, but if for example you are an author with an editing "team" of 10 people, and nine of the 10 tell you that this or that doesn't seem right, you can be pretty sure they're correct, unless it's something you've done on purpose. In addition, by being a part of the team, they get to discuss their impressions of the work(s) in question and perhaps form a consensus of their impressions.
Also, it is not uncommon to see, in any book, whether electronic or paper, an acknowledgement from the author for the help provided by others to ensure the accuracy of the book. How is this any different from a "professional" editor?
These studies that claim lost revenue really baffle me. Predicting how many copies of a piece of software, a video, a song, etc., a company is going to sell is impossible. The sales predictions are affected by too many variables to be accurate:
a) If your product is no good, even if you believe otherwise, it's not going to sell;
b) it might not be promoted well enough;
c) economic issues (recession, market crash or upswing) affect people's buying power; and
d) too many other issues to enumerate.
All this to say that claiming you're losing money to the "pirates" is akin to my saying "I had an idea a while back but couldn't sell it, so I've lost $50 million dollars!" In other words, pure and utter bunkum!
According to the financial columns I've read, these industries are doing just fine financially, after all, they've been gouging the public from their inception, as well as the artists who provide them the material for sale. Sooner or later, they're going to realized they are doomed though, with the availability of the web, artists, authors and any creator of media is going to be able to personally market themselves and their creations.