Q:

Shouldn't responsible/sensible deletion of (old) questions imply looking at related ones too?

Admittedly I promised myself to stay clean of the inherently difficult recent discussions regarding deletion of questions (e.g. Question deletions are getting out of hand and The Great Question Deletion Audit of 2010, but alas ;)
Being 'hit' again another time by answering an old question only to observe it being deleted shortly thereafter I wonder about the moderation rationale/policy regarding this, I presume it works like so:

Somebody (i.e. me in this case,
see the Google Cache in case you
lack the reputation)
answers/comments/edits an old
question.
This triggers the question
to be 'active' and consequently
attention by high reputation users
and/or moderators.
They look at it, wondering what the fuzz about this
old one might be and decide to vote
for deletion (or delete it right away).

Now, in principle this is fine with me, as mentioned I do not want to discuss whether or not to delete etc., but:

Any casual user might be quite surprised why his activity triggers deletion, while other related and often pretty similar questions stay untouched and prominently visible while puzzling around still. To continue on the example there are several low quality questions linked as related that might be candidates for deletion too then, e.g.:

Status of the Stackoverflow API
StackOverflow API, is there any progress in this area?
API(pre-alpha) link
API for accessing stackoverflow? (closed) [deleted too meanwhile]

Granted, the question I provided an answer for might have had a somewhat more offensive tone (the author appended a disclaimer though), but I think the well reasoned answers provided there do actually deliver more value than several of those to the questions mentioned above, YMMV of course.

Again, I'm not opposing the deletion, just questioning the chain of events and decision transparency.

So I wonder: Shouldn't responsible/sensible deletion of (old) questions imply looking at related ones too?
I don't want to judge on or even ask for anybodys time allocation, but I'd think having a quick peak at related questions while voting for or performing a deletion should be quite fast and actually benefit the very intent of the actor, shouldn't it? This could improve fairness, transparency and, not the least, the quality of the sites content even further, IMHO.

A:

See these posts:

why-my-cw-was-closed
why-was-my-question-about-the-matrix-closed-closed
why-did-my-question-get-closed-as-subjective-when-other-clearly-subjective-questi
why-is-there-a-double-standard-regarding-non-programming-related-questions-at-so

These posts are all about the fact that certain questions will be closed for "little or no reason" when other questions of a similar nature are left open. 
As noted by TheTXI, this is a logical fallacy that assumes that the other questions were under the same scrutiny when they were asked. 
StackOverflow has a two year history, during which the community has evolved. Therefore older (similar) questions may have been asked at a time when the community was still attempting to set boundaries, and we did not yet have Meta to discuss issues like this. (We had UserVoice which was not as amenable to discussions of this nature.)  Older questions like this get "grandfathered" in, in the sense that they are so old and have a large number of answers and votes, so they can't be deleted.
Additionally, even now, StackOverflow is moderated by the users, and the users are not a single-minded body, but rather a large group of people sharing a common interest (but no coherent singular opinion). There are daily waves, the peak of usage is around midday in New York (IIRC). This means that the users who are voting to close at noon (your time) are not the same users who are voting to close at midnight. Additionally, questions can similarly sneak by on the weekends. 
This is an issue in every judicial body that has enforcement that requires interpretation. It absolutely does not mean that every open question is valid. When questions are closed and similar questions are left open, it generally means that the open question should be closed, and not the other way around. 
Now, onto the meat of your question. 

Shouldn't responsible/sensible deletion of (old) questions imply looking at related ones too?

No. It does not mean that at all. All moderation is done based on attention. The moderators monitor the front page, and check out the flagged posts. The users with delete ability use the site as they normally do, and vote to delete when they notice something worthy of delete. The same applies to all those who are voting to close. All of these users are volunteering their time in order to try and clean up the community. So the fact that they are voting to delete at all is helpful. (Ignoring the question of whether or not their vote is valid, they at least felt that it was). 
The most important thing is cleaning up the front pages (Hot, Active, Newest, etc.) because this is what the bulk of the users will see. 

