The dev team always has to mop up when someone in marketing or sales, etc. doesn’t know how to say no.
Perhaps you should give some thought to the following items:
- If all the company does is write code, they go broke. They only make money when they SELL code.
- To that end, the sales people are paid big bags of money when they SELL something. So, it is in their best interests (and that of the company’s) to say YES, whenever it is feasible to do so.
- They are not trained to know what is feasible and what is not. That’s your job. :-)
Years ago, an old grizzled software salesman I used to work with said this. Never forgot it:
“My job is to drag big bears through the front door. When I do, you might say “what do you expect me to do with this bear?” My response is “That’s your problem. I’m going out to find us another one.”