Is there really any uncertainty over how to respond to them? Aside from the bridge question, I think our building questions have been well-written and tightly scoped.
Obviously people can have different opinions about styles, resulting in very different suggestions. That doesn't make the question subjective, any more than any e.g. programming question is subjective. Just because there are several good, conflicting answers doesn't mean there are not objective standards to separate good and bad answers, nor that the asker and community cannot use their own opinions to promote or demote answers. Rather, that's the point of crowdsourcing. Problems arise when there are dozens of answers and no way to decide between them. I expect there are probably at most five ways to build a sphere, and ten ways to build a micro-scale crypt, and the situations askers and voters find themselves in provide enough objective criteria to make a good decision between those.
This is also why there's two axes of rating answers on SE sites. The first is, what was the best answer for the asker? And the second is, what does the community deem the best answer? The former is decided by the answer tick and the second is decided by voting.