Emergency Argument Tactic #3 (only to be used if primary tactic is defeated)

Yeah, but don't use your straw men to trivialize the difference between "misspent" and "invested."

What if those folks' homes had been bulldozed not for a gelatin sculpture, but for a new school for underprivileged children? Then wouldn't it make more sense to finish the job than to cut and run?

There is an important difference between misspent and invested.

However, resources that are lost no matter what one does are always a very poor basis for decisions about the future. No redoubling of effort nor refusal to continue will change the fact that things have been lost.

In many situations, as in your example, decisions are ideally made looking to get the best outcome from the present circumstances. If the school for underprivileged children could do a better job at less future cost somewhere else, we would have to be about as sharp as a marble to build it where those folks’ house used to be.

At best, arguments based on already lost resources muddy the waters with irrelevant, unfortunate, and often emotional information.

In Economics, this is known as the sunk cost fallacy...here's the Wikipedia article: http://en.wikipedia.org/wiki/Sunk_costs#The_sunk_cost_dilemma