There are a lot of industries that rely upon the weather. Big, important industries. Tourism, obviously, since nobody wants to visit an attraction while the weather is poor. Construction and agriculture are obvious, too, since many construction jobs can't be done when it's too cold or too wet, and crops are variously sensitive to the weather as well, and either can't be grown or require expensive interventions. Many kinds of entertainment depend upon the weather, too, including sports. That, in turn, affects retail, restaurants, and other kinds of entertainment: a sports game attracts people to sports bars, but if a game is delayed due to weather, those people will often go shopping, watch movies, or go to family restaurants. Severe weather, including earthquakes and hurricanes, can disrupt some businesses - like utilities and oil refineries - and stimulate others, like construction and disaster relief suppliers. The weather is arguably the single strongest macroeconomic influence.
So in order to predict macroeconomic outcomes, you need to be able to predict the weather. Likewise, to change macroeconomic outcomes, you need to change the weather. The United States is a superpower, but it can't change the weather*. And I'm not sure what stories the Republicans tell each other about George Soros, but I'm pretty sure he can't change the weather either.
Basically, your post was a non-sequitur. The question of whether or not "macroeconomics" is "useful" is not helpful, because I don't think the person asking the question understands either what macroeconomics is, or what useful should mean.
A few months ago, you suggested, for example, that government tax revenue might actually increase after a tax cut. This was, in your own words, a take on the Laffer Curve, a bit of pernicious macroeconomic reasoning that was invented by Ronald Reagan's cabinet to support his own tax cut. So it doesn't seem like you have a problem with macroeconomics, per se, or even a problem with how the government is using macroeconomics to support their political agenda. I actually have no idea what your grievance with macroeconomics is, then, since you've previously found macroeconomic arguments quite useful.
Macroeconomics is literally a study of the whole economy. Is it useful, for example, to estimate how household energy expenditures might be affected by a severe hurricane in Houston? Because that's a macroeconomic effect. Answering this question is obviously useful; this specific example is a matter of strategic significance.
Is macroeconomics useful for setting broad policies? I don't think it is. It's not normally possible to perform studies the same way as e.g. medicine does them. You can only infer results from found experiments, and try to rule out confounding variables. This is a major limitation and, in my opinion, macroeconomics is only useful for describing what has already happened, and it is not useful for policy selection. But at the same time, you don't seem to have an actual problem with using macroeconomics to set policy. Which only leaves the descriptive part of economics... like you have a problem with people looking at what's already happened, and reporting on the root cause? That would be a ridiculous complaint.
So what's this comment about? Is macroeconomics just some republican whipping boy now, or what? Where'd you hear this stuff about macroeconomics?
Edit: Updated to more accurately reflect my sincere confusion about Wookie06's complaint.
Edit 2: * Weather and climate mean different things. Don't even ****in say it bro.