Do you think that has anything to do with the incentives for reviewers, who want shorter papers with a length limit and prefer more details on the impact/why of the experiment?
Does the same method-hiding hold true in journals without length limits or different review processes?
In the software world, Bioinformatics has 2 page application notes[1]. That is nowhere near enough room to have a figure, describe an algorithm, and describe results. In cases where the source code is available, I've found the actual implementation often has steps not described at all in the algorithm. And these differences make a clean room implementation difficult to impossible if you want to avoid certain license restrictions.
Since it has been a decade since I worked in a wet lab, I'm less familiar with examples in that world, but I know not offending chemical vendors is a concern for some people in the synthetic chemistry world. At a poster session, they'll tell you that you shouldn't buy a reagent from a particular vendor because impurities in their formulation kill the described reaction. They won't put that in a paper though.
Does the same method-hiding hold true in journals without length limits or different review processes?