Earlier quoted context omitted.
What's stupid in wanting to get an idea of how much a project costs in order to decide if it's a good idea to pursue, let alonr allocate resources?
Nothing, inherently, except perhaps the fallacy of comparing a pair of jeans to the rather chaotic and unpredictable world of bespoke systems development. One is inherently known (a pair of jeans you've presumably already manufactured), the other is one big unknown, basically.
"Ok, how long is this project going to take?"
"Well, it's still being defined..."
"What do you mean you refuse to tell me how long this project is going to take?"
The analogy is so ridiculous that the person making it clearly doesn't even comprehend the domain he's discussing.