When a site suggestion might be reviewed depends on how many suggestions there might be in a particular category, how many editors have editing permissions there, how busy those editors might be doing other things in the Directory, how much free time those volunteer editors can devote to editing from their real life, and when those particular editors get the urge to review site suggestions there.
Editors have many other jobs to do besides reviewing site suggestions, and because we are unpaid volunteers giving of ourselves to a worldwide Internet community of web surfers, we have the freedom to pick and choose our activities, and when, where, and how much work we want to do.
That's why we can't predict any times or results for site suggestions, it's very random work. I've reviewed and listed site suggestions that have only been there a day, and others that have been there a couple of years.
Is that any particular editors fault? Absolutely not.
For example, if the State of Blank, only has a total of 5 editors, and four of them only edit in their particular locality/city, that leaves one State level editor to edit the rest of the site suggestions in the whole State.
Whose fault is it? If it is anyones, it's the people of that states fault, for not caring enough to volunteer their free time to put their state on the Internet map.