Yeah, the issue is not that pork spending goes into space and disappears out of the economy. It doesn't, it's still being spent and generate jobs and etc.
The issue is that governments must make investment choices with limited resources at hand. So every time money is invested in something that will deliver inferior returns than an alternative, money is indeed being wasted from an economic POV, it's indeed being blown to space.
So, I think everyone here is 'more correct' than the person who's debating with them seems to understand. In some ways, you're trying to buy different things. Pork spending that triggers a multiplier effect is a really great way to equalize a local economy. It brings in jobs. People really like jobs. They use the income to improve their lives in ways no bureaucracy could ever predict, from buying clothes to buying education for their kids. This money will pull 'ROI' into an economy in ways oblique to the actual spending, but it will depend upon the wisdom of the local citizenry and the level of the multiplier effect that they can achieve. It's best to think of it as workfare, but it's nice if the pork buys something nice.
Pork spending that generates an ROI is also really great. It doesn't even need to be a direct ROI (like a new tollbridge), but can generate revenues through secondary mechanisms (a new road can increase trade, which would increase taxation revenues). Now LOTS of budget hawks are not alert to that second possibility, and maybe for good reason. It's hard to measure, and it's hard to predict. It also will be successful based on the wisdom of the bureaucrats, less on the local citizenry.
Now, in an ideal world, gov't spending would be able to do both. On this front, I think Stiglitz was more correct than not when giving his prescription for the Great Recession.
The big difference here is the potential timeframes, which is what can get politicians in trouble. A workfare project with a multiplier effect brings very rapid perceived gains to the community. It can even very quickly raise people's quality of life, especially through some really (emotionally) important thresholds. A good ROI project can take a long time to generate returns, and might never generate noticeable returns. They might be invisible to both the local community, and to the populace at large. By the time a good project is clearly generating an ROI, there are a bunch of pocket industries supporting it, building off of it. So, the initial investment looked obvious in retrospect.
Now, my bias is to be an 'ROI'er, easily. But, the older I get, the more I can appreciate the local benefits of the multiplier effect. That multiplier effect can make local 'welfare' spending vastly cheaper than it seems to be on first pass. Incredible bang for the buck.