The problem with considering long term effects and indirect consequences is - it's hard, and often there's no way to know for sure what the consequences will be.
If we have 2 opposite effects going on, and one school of economics says this one will be more powerful, and the other says the other one will be more powerful, and there's no way to know who is right, then how can we expect people to consider these effects, if people don't know what the efects will be.
Short term effects are mostly obvious. Long term effects are harder to predict, and people suck at estimating probabilities. So it's easier to ignore the long term effects altogether.
If we have 2 opposite effects going on, and one school of economics says this one will be more powerful, and the other says the other one will be more powerful, and there's no way to know who is right, then how can we expect people to consider these effects, if people don't know what the efects will be.
Short term effects are mostly obvious. Long term effects are harder to predict, and people suck at estimating probabilities. So it's easier to ignore the long term effects altogether.