Specular highlights are cheap (frame time and artist time) and beautiful when done right, so everyone tries to do them and they get overcooked.

There is a secondary problem in big budget games where modeling work gets farmed out leading to selection for "what looks good in the preview pic." In the preview pic, the asset artist gets to choose background/scene/lighting, and it's an easy trick to choose them to make the specular highlights pop. The person doing integration buys the asset, drops it in wildly different background/scene/lighting, and now the specular highlights are overcooked because the final scene wasn't chosen for the specific purpose of leveraging specular highlights.

tl;dr artists ship the org chart too