Some searching on http://meta.stackoverflow.com came up with the following:
- According to http://meta.stackoverflow.com/questions/87890/why-cant-i-suggest-edits-on-se-meta-sites/97371#97371 it's due to the fact that it would add an another burden to moderators which is explained by the following:
Mostly because the per-site metas are generally low traffic -- some of them count daily visits in the dozens.
That means the moderators will have to do the work, since the 10k site users are the only ones that can even see this queue. And on many sites, like say Bicycles -- there are exactly zero users at this rep level, even after many months.
[...]
We were uncomfortable adding Yet Another Queue for Moderators to Look At across every site in the network.
- According http://meta.stackoverflow.com/questions/78223/per-site-metas-dont-have-ability-of-suggested-edits/78319#78319 (which is older than the above answer) it's a feature that is not needed on meta sites.