I have gained little from completing the Horizons program. Disillusioned with Chevron's mismanagement of young engineers' careers, I left the company soon after.
In hindsight, I wish that when leaving school I had the insight to go work for an oil&gas supplier/constructor, but the Chevron recruiting pitch sounded pretty good, and I went for it. So for all those out there hating Horizons, please be able able to distinguish between the program itself and people in it. Young college grads joining Chevron do not have the option of not joining Horizons.
But if your argument is that Chevron should change its recruiting policies and stop recruiting college graduates, that's a whole different topic...