"It's not like you _have_ to use IP multicast to solve certain classes of broadcasting problems" Then why did NATO get their own dedicated lines to multicast o

"It's not like you _have_ to use IP multicast to solve certain classes of broadcasting problems" Then why did NATO get their own dedicated lines to multicast on? Why don't they run their 100,000 simultaneous user systems without multicast and save that expense? But OK, we'll pretend you're right about that one. What if someone asks for a job shop scheduler for predictably giving optimal schedules for 300 machines interactively? NP completeness is no problem, right? Or what if someone asks for an in software modulator for the entire radio spectrum? The non-existence of the necessary hardware is again no problem, right? Or how about when users asks for just plain contradictory requirements huh? Never happened to you? Because these ones are not just physically impossible but also logically impossible. The fact is that some things are constrained by engineering. It is also a fact that some non-technical types in positions of authority push back when told "no" because of technical constraints, and ask "Why not?". Attempting to give them a reason is a trap, because they are asking the question as an opening negotiating ploy. Because these idiots in their ignorance think an engineering constraint is a negotiable item. I feel very sorry for the engineer in the original post because it sounds like he's stuck in such a rut. And it's simply infuriating to hear somebody respond to that plight with the nonsense that "in IT anything is possible".