Canonical answers are okay as long as they fit within the rules of attribution and bounties are okay as long as they aren't meant to abuse the system to exchange rep.
As Servy pointed out in comments:
all user contributions are under the cc-wiki license. And more specifically:
You cannot prohibit others from incorporating content you contribute in their own answer.
He goes more in-depth about that in his answer:
It is entirely appropriate to add a new answer to a question that takes information from one or more other answers (on that question or elsewhere) and quotes, summarizes, or paraphrases content of theirs to create a single answer that they feel is better than the others. So long as they properly attribute the content taken from the other answers.
Posting a bounty asking for someone to do what is described above and to condense/refactor/combine one or more answers into something they feel is "better" is just fine.
In this case, the answer does state that others have helped, but it's not really specific as to where the content is taken from, or what is original vs not. I don't feel it does enough t be considered proper attribution, but the resolution here is to simply edit it to link to the posts/comments that were incorporated into the post, and to be more specific, in the post, as to what content is not the author's.
the answer from Robert Harvey tells us more about when bounties are disallowed:
Bounties are only disallowed when they are being misused to:
- Transfer rep, or
- Overly promote a product.
Case in point : the content above is just annoying everyone and generates downvotes.
The reasons I dislike to see answers copy-paste content are:
- not 100% of users give proper attribution,
- that the content is already there, and it is just a waste of electrons,
- users can simply summarize another answer and link to it (in the example above, I simply didn't)
Let's take the scenario:
- answer #1 contains content A (original content)
- answer #2 contains content B (original content)
- answer #1 is modified to also have content B (in other words, content A + content B)
- author of answer #2 does not want to modify answer #2 to also have content A (content A + content B) because answer #1 and #2 would be identical.
- answer #1 gets accepted.
Both authors have their original content, then bounty comes in to "encourage" canonical answers. This shifts people attention from creating helpful new content to aggregating answers, which is a questionable activity. In the case where numerous answers are present and we need to sort things out I could see the benefit of such bounty; however when the number of answers is just a handful that is very much unnecessary.
A related question has already been tackled: Accept Multiple Answers or Split Bounty among Several Users. The answer to that question goes along the lines of "no, let's not mislead people into thinking this is not a competition". In other words it's a race, for both authors featuring great content, whoever get the all-inclusive answer first (by means of copy-pasting / summarizing or otherwise) wins. (I have a problem with that approach when the answers are not community wiki).
Another related question on this topic: Is it acceptable to add a duplicate answer to several questions?, we know how to handle duplicate answers to different questions, but handling duplicate answers to the same question is a grey area which we are trying to solve here... or maybe not. I guess the question: Why Isn't There a Way to Consolidate Answers? gives clues on how answers are consolidated on SO.
What if both authors do the same thing and come up with the same compiled content though? Why shouldn't they get both rewarded? "Oh wait... I look at the timestamps, this guy there was second, he must have copy-pasted". I wished that in those cases, the question would be made community wiki (What are "Community Wiki" posts?) and answers were made community wiki.