I think that especially with the Internet not bounding paper lengths any longer, authors should write more comprehensive versions of their papers (or at least include an appendix).
In most cases, the succintness of the papers is what makes them difficult to read, both in terms of skipping steps in proofs and in terms of hidden assumptions of the reader's knowledge.
Psyklic, our UW QSE group felt the same way, and to remedy these problems we wrote a 96-page "Practical Recipes" article on quantum simulation, which appeared this month in the (open source) New Journal of Physics.
This length permitted our QSE Group to explain practical methods for quantum system engineering at a mathematical level that was well-matched to our quantum system engineering students.
On the other hand, the peer review of articles of this length is a lot of extra work for all concerned---reviewers, editors, and authors ... to say nothing of the effort demanded of the readers.
In most cases, the succintness of the papers is what makes them difficult to read, both in terms of skipping steps in proofs and in terms of hidden assumptions of the reader's knowledge.