UGH, I hear your frustration. While I get Doug's point about politics, I think there are some pieces of information that could help you.
One of the worst misuses of the Lean Startup concepts is skipping straight to building something in code. I think the catchphrase of the Build, Measure, Learn loop throws people off, because they think they need to begin with building something. In reality, Eric Ries actually suggests starting with a period of getting out of the building to talk to people and confirming that they have a "significant problem worth solving" (which is UX research...that quote is from page 88 of Lean Startup - Show your colleague!) It's after this first step that you're supposed to leap into the Build, Measure, Learn loop, and even still, the goal is to get through the entire cycle of learning as fast as possible, not just building something as fast as possible. This is a big semantic, but the focus on working code is a tenet of the Agile development process, which isn't actually the same thing as Lean Startup.
To get back to the Lean Startup feedback loop, you're supposed to begin by building an MVP (minimum viable product), which is whatever you can build with the least amount of effort that allows you to test the the hypothesis, which means it could be anything from a landing page to wireframe to a sketch, as long as you can test your hypothesis out and decide whether to keep on the same path or pivot to a new solution. With this lens, you can argue that you save time when you learn by testing (and possibly pivoting away from) a wireframe rather than a working piece of code. The whole point is to get through the entire learning cycle as fast as possible.
For more reading on this, checkout https://www.agilealliance.org/build-measure-learn-lean-startup/