Yes, he did thank the engineers and designers in his keynotes – COLLECTIVELY. However, he also specifically abolished the previous practice of naming all software engineers involved in OS releases.
Admittedly, there were plausible reasons given for this, but I felt that ultimately, the reason why Pixar gives personal credit to their movie contributors, while Apple does not do the same for its engineers, is that our industry is not unionized.
I read somewhere that this was because of concerns with talent getting poached by other companies (which was especially a concern in the early days of OS X, when Apple was still "beleagured". Still, point taken; there are lot of unsung heroes within Apple's ranks.
Admittedly, there were plausible reasons given for this, but I felt that ultimately, the reason why Pixar gives personal credit to their movie contributors, while Apple does not do the same for its engineers, is that our industry is not unionized.