The problem you had was that you were trying to convince management to act in the best interest of the company rather than their own best interest. They would much rather be in charge of a $100k a month project instead of a $1k a month project. Also the big solution required a bunch of engineers working full time which puts them higher up the ladder compared to your 1 engineer working part time solution.
You were saving the company money but hurting their resumes.
You were saving the company money but hurting their resumes.