Ignore the question entirely. If it is so poor that trying to answer it will be a waste of your time, then why waste any time telling the author so. Make no response to the question at all -- no downvotes, no close votes, no comments, nothing.
If someone else with lower standards or more free time than you elects to engage with it then so be it.
Accept that as a good citizen of an SE community, you share responsibility for policing its standards and make that minimal commitment. Cast a downvote or a vote to close or both (as appropriate) but do not provide any explanatory comment.
The author may choose to rail against the "system" or a "closed cabal" that rejects his or her work but you avoid the risk of further inflaming the situation with words that could evoke an emotional response.
Recognise that simply labelling something as needing improvement does nothing to meet your community obligation to raise its standard and edit (or even, rewrite) the question until it is acceptable (in your eyes).
If others have a different view, then they can make further edits or roll-back until we arrive by an iterative process at something that we can all accept as meeting the relevant criteria.
Acknowledge that community members share a twin responsibility to maintain group standards and to grow individuals. Add a carefully-worded comment that identifies the perceived fault and draws attention to a suitably extensive discussion of how they might be remedied (such as https://genealogy.meta.stackexchange.com/a/1694) because short-hand comments are notoriously hard to interpret.
Offer to discuss the strengths and weaknesses of the question (which should be considered a working draft) in a chat session. Engage in a collaborative editing process with the original author until both parties are satisfied.
Stop being so pedantic and just answer the question. Assume that (over time) the author will absorb whatever essence of good question permeates the community and their questions will improve as a result. Let them learn from their mistakes without emphasising the fault.
Embedded within the above options can be found the operating assumptions of a number of web-based groups with which SE shares some charactistics (and with which it claims to compete). IMHO this group is suffering from not having a consensus view of what is the SE:G&FH way.
However each one also reflects an individual perspective based upon personal philosophy and predisposition. I mean no disrespect when I say that I checked my list by asking "How would ... answer?" (You may wish to insert user-names against each option as a (private) exercise.)
When the personal position repeatedly comes into conflict with the corporate (either that centrally espoused de jure or the one currently prevailing de facto) then each individual needs to ask "Is this the place for me?"