FWIW (not very much) in the software industry people have this kind of problem all the time. A developer can't offer sensible, achievable features because they wouldn't get the contract. So they have to be bull****ters to make a sale.
There's some finite time or amount of money available so there has to be some invented "reason" or other for ignoring experience about how long things take or how much they cost. In software the current "reason for ignoring experience" is agile development which, sort of ironically, is about how to cut features to fit time and budget. Nobody actually does it properly because their contract specifications would not be met. Contracts are written at the beginning of a project when everyone knows the least about how feasible each feature is.
Ultimately it's all an excuse for coping with human problems of trying to decide what you want before you understand all the problems fully and not being prepared to pay a reasonable price for a reasonable outcome. To get the money, magic must be promised.
Last edited by t43562; 13th Oct 2014 at 07:10.
Reason: clarification