Reactive management is not terrible if it can be used correctly. If the manager still applies himself and is able to keep the long term goals on track, and able to accomplish their own tasks at the same time (without being swamped in emails) then it is great. But this often doesn’t happen. The problem becomes when they put off the long term work to much and create newer short term problems that just keep stacking.
There are suggested methods to “breaking the cycle” of constantly putting off long term work to solve the short term problem that was made because you had putt off previous long term work. The way that I see it, is to handle every problem with your full attention. If you are given a problem then you should truly evaluate your plan of action and determine what will have the best outcome. I think this also means more communication and meetings between members and having a manager who is good at balancing their own work as well as being open and able to think long term. It may be harder/ more work for a reactive manager to do this, but this is why they are in that position so they should be able to handle it.