The real reason this is a less than ideal solution is that, even assuming it works perfectly, and even with other forms of cooling, increased atmospheric carbon

The real reason this is a less than ideal solution is that, even assuming it works perfectly, and even with other forms of cooling, increased atmospheric carbon concentrations still contribute to ocean acidification and other chemical effects. But you're right that The Climate Change Movement™ dismisses these things out of hand. This is because it is only incidentally about combating climate change. It is primarily about giving more power to approved politicians and bureaucracies. This is also why we have made no almost progress on the underlying issues. We were never meant to.