I'm in favor of making the reason both clearer and stricter. I think your example edit is far too minor, although I should say that I don't think that, on its own, it is a cause for tremendous concern.
A large part of the kerfluffle today was the fact that the minor edits under discussion were also massively serial. The user making them had apparently done a search for a misspelled word in question titles (I believe there were at least three different words) and was single-mindedly fixing only that issue, across hundreds of posts. Many, if not most or all, of the posts had multiple other issues that were left unaddressed. The one you've linked to has two sign-off lines, a tag in the title, a misspelled word ("overlayed"->"overlaid"), could potentially use some code formatting and more specific tags, and (for a bonus edit) has bullet points that are (ahem) pointless.
Should we expect the user to have caught all those items? No, but at least one of them -- sig lines -- is glaring and would have doubled the quality of the edit while requiring only a little further effort.
The usual response (most recently expressed by Robert Harvey and NullUserException) to concerns about too-minor edits is "What is the harm?", or "Every little bit, no matter how little, helps." I haven't found a thorough and unequivocal rebuttal of that response; admittedly at the risk of running a little outside the bounds of your question, I'm going to provide one here.
A number of users expressed indignation about the rep or badges that are gained from such edits; this is, to me, not the main point. Rep is in some way significant to all of us, and I can sympathize with the view that a badge like Strunk & White is devalued by trivial, serial edits, but I am more concerned with the following:
First, other users are prevented from making any improvements on a post while a suggested edit is pending. If another user comes along and wants to make a substantial revision, the only option is to wait until the trifling edit has been acted on by reviewers. If this other user doesn't want to or can't wait, or simply forgets to come back, then the post languishes unedited. This is harmful.
Also, the suggested edit queue is a fixed size. When it is full, no edits can even be suggested until it clears up. The user under scrutiny today went a fair way towards (if he did not actually accomplish) filling the queue up himself. If two or more users took it into their heads to make tiny edits like this at the same time, it would actually prevent more thorough, more valuable edits from being made.
Next, as waffles mentions twice, reviewing suggested edits takes up time. Users with the time, inclination, and privilege to review edits are not infinite. To determine whether any given edit is actually helpful takes a moment and some effort. If reviewers get frustrated by feeling that they have to do more to every suggestion (see the answers on Do we need a 'reject and improve' button?), or that their time is being wasted rubber-stamping edits that could be performed by a machine, they may review less thoroughly or less often. This is harmful.
Further, if a significant portion of edit reviewers believe that a class of edits is bad, then, a) democratically speaking, it probably is bad, and b) in order to keep them happy and continuing to review, perhaps it should be considered bad.
Another "flooding" issue is that any edit, no matter how minor, makes the question active and bumps it to the front page. This is by design, to get eyeballs on an edit (a defense against malicious edits, even by users who don't need to make suggestions) and to allow OPs to "freshen up" their questions or answer in hopes of more attention and votes. What this means, though, is that massive, petty edits push newer, active, interesting questions out of a very popular view. This is frankly unfair; it harms the ability of askers to get as much attention as they can (and probably irritates some users of the page).
Next, a post is automatically converted to Community Wiki mode when it is edited by at least five users. Every edit, no matter how piddling, moves a post closer to this. When the post is converted, the owner's reputation is no longer affected by votes on the post. When the post is further worked on by an editor making real improvements, the count is higher than it reasonably should be. An insubstantial edit harms the owner of the post.
There's also a signpost issue, especially in the case of this search-and-edit program. When a single easy-to-search problem is removed from a post that needs more work, the post is made more difficult to find by editors who actually want to complete the corrections.
Finally, a statement of my opinion: I don't think that hundreds of title typo edits are anywhere near as valuable as a dozen careful, comprehensive cleanups of entire questions. Title edits are often held up as the single most helpful thing any editor can do, the idea being that incoming visitors see titles first. I don't agree generally, and certainly not in the case of simple spelling errors. Making titles clearer or more specific is one thing; adding a missing character to a title and leaving the rest of the post just means that visitors will be lured by a pretty sign, order a meal, decide the food is crap, feel cheated, and never return. When a huge number of negligible edits are being made, brakes should be applied.
Edit suggestions which fail to address a majority of the problems in a post should be rejected. The volunteer labor of edit suggesters is valuable, but not more valuable than that of reviewers. Suggesters should be inculcated with the idea that thorough, substantial, even bold, edits are the proper, most helpful, procedure on Stack Overflow. To that end, the rejection reason should be worded more strongly:
This edit is insubstantial; suggested edits should be comprehensive improvements addressing a majority of the issues in the post.