The ability to notice a flaw isn’t the same as the skill, experience, and background that might be necessary to design a useful solution for a particular issue, especially complex issues. It’s generally reasonable to say, “I don’t know of a better solution, but I can predict that x and y problems will likely result from your proposed solution.”
It’s especially valid to warn someone when their proposed solution will harm people or make things worse. You don’t have to have a better solution to try to prevent someone from doing something ill-conceived or hasty or reckless.
If the stakes are low or the person proposing a solution is likely to be sensitive to criticism, it might work better to try to approach your response as an attempt to help them refine their solution, rather than just opposing it outright. Be considerate of their feelings and make it clear you’re working together.
Generally, no, but context and approach matter.
The ability to notice a flaw isn’t the same as the skill, experience, and background that might be necessary to design a useful solution for a particular issue, especially complex issues. It’s generally reasonable to say, “I don’t know of a better solution, but I can predict that x and y problems will likely result from your proposed solution.”
It’s especially valid to warn someone when their proposed solution will harm people or make things worse. You don’t have to have a better solution to try to prevent someone from doing something ill-conceived or hasty or reckless.
If the stakes are low or the person proposing a solution is likely to be sensitive to criticism, it might work better to try to approach your response as an attempt to help them refine their solution, rather than just opposing it outright. Be considerate of their feelings and make it clear you’re working together.