What you are telling sounds interesting, perhaps you could give a published reference? Were you one of the participants? Anyway, you would agree that in a corporate structure, such as Kodak or Ilford, some people do the R&D and others make decisions as to where the company would go, and those are not necessarily always in agreement. It is pointless to see chemical or economical reasoning in this. Speaking of Haist, he reiterated the message of how important it was to go for the least toxic ingredients, as he mentioned that large numbers of untrained (in chemistry) people were entering photographic processing. So, suppose someone's developer contains p-aminophenol, p-phenylendiamine and hydroquinone, each necessary to its unique properties. This kind of composition is totally in disagreement with the low toxicity trend. However, you can also envisage some propaganda moves to discredit certain chemicals in favor of others. If you ever had a look into what women all over the world stick onto their scalp when they dye their hair, you would know what I mean. BTW, "low toxicity" does not mean you can be careless around developers containing phenidone and derivatives.