Why does it take so long for pokestops nomenations to get accepted?
How long does it have to be in queue to get accepted ?
welcome to the forum!
there is no concrete answer we can give you. some can be decided in hours (maybe minutes) and others take months.
if your nomination is taking too long for your liking to be decided, you can review nominations. that will help clear out the queue, and you can earn an upgrade to send your nomination to a wider review pool.
be aware that you submit wayspots, not pokestops. they may be accepted or rejected in review.