Well, to get around the problem of disagreeing about which policies are wasteful and which are not, we can rely on evidence based policy making. Identify a policy goal, and how much it costs to achieve that goal. Then you can compare the policy to others to help determine which are good policies (assuming you agree with the goal) and which are wastes of money.
A fantastic example is the public transit tax credit. Its stated goals were to reduce GHG emissions and reduce congestion. I didn't see any stats on the latter, but there is little evidence that transit ridership has increase appreciably because of this credit, so it's unlikely there was much impact on congestion. On GHG emissions, it's been estimated that this program costs ~$10,000/tonne of CO2e emissions avoided. That's an abysmal failure and a waste because there are any number of policies that cost much less per tonne CO2e offset. Same goes for congestion/ridership.
Same goes for the ECO/Energy retrofit program. It's better than the transit tax credit, but the cost per tonne of CO2 avoided is fairly high. If CO2 reduction is a priority, it's better to let the market find the cheapest ways to reduce emissions by setting a carbon tax and varying it until you attain your desired level of emissions reductions. If you use the revenues to reduce other taxes, there should be no net negative long-term economic effect (it might even be positive, depending on which taxes you cut).