I have recently thought about this a lot. I don’t solidly know, but there used to be, I feel, a greater belief in chemistry as a tool to make life easier, literally expressed in the slogan “Better Things for Better Living…Through Chemistry” that Dupont used 1935 - 1982. The idea of creating new chemicals for consumers seems to have since become unpopular.
In addition to that, there is increasing leanness of companies’ operations. A very big deal is “outsourcing a lot of jobs to contract organizations in India and China,” as scout59 said. The production of chemicals (like other manufacturing) has been largely shifted to countries where it is cheaper to make them. The manner of producing these chemicals is probably well established.
Jobs difficult to send overseas are analyses of food and environmental materials that have to be done quickly. However, I have seen increased use of people with negligible or no chemistry education doing the analytical testing in environmental labs. (You don’t really need to know much chemistry to do these procedurally fixed tests, and the lab owners were sure to find that out someday.) Still another thing is the drive to have as few full-time, permanent people as possible, because of the health insurance and other costs associated with them.
http://chemjobber.blogspot.com/2012/04/bls-historical-estimates-of-job-growth.html shows the decline in people employed as chemists from 96,000 to 82,200 during 1998-2010.
(I have many times cited Bureau of Labor Statistics projections of occupations’ job growth on these forums. However, I have come across signs that the BLS is sometimes quite off the mark. The table at the cited webpage is hard proof there’s reason to avoid depending on BLS predictions, because early in the period covered by the table it predicted large growth in chemist jobs in the US, but what happened is decline.)