The researchers deserve some of the blame as well. In physics, at least, and certainly in some other fields, there is a strong tradition of posting preprints to the arXiv or other similar free archives. The journals, including all the top journals, accommodate this---they have no choice.
You mention chemistry. I don't know anything about chemistry journals, but given the precedent set by other fields, I feel that chemists don't have a good excuse for locking their research up behind paywalls.
You mention chemistry. I don't know anything about chemistry journals, but given the precedent set by other fields, I feel that chemists don't have a good excuse for locking their research up behind paywalls.