First: I totally get your point, I am also bugged by the obvious spam.
But here is the but: We have already reduced the misuse by capping it at 100 words and not allowing loops. Plus, Pleu already mentioned the GSAK users (German cachers are still a big user of GSAK), which would continue doing spammy logs.
One big problem is that most of these people only realize about the badge after having found hundreds iif not thousands of logs. And to balance their very short log word count, they usually massively enlarge their logs after that. There would be an elegant way to increase the number, though: Editing old logs (at least on caches still active), the word count will go up. But of course that takes way more effort than simply maxing future logs. ;)
An extensive "spam filter" takes just too much work to set up and maintain. One option (instead of removing the badge altogether) would be further decreasing the requirement. On the other hand: if it is too simple, we could get rid of it.
PS: I admit that I also kind of "bloat" my logs a bit with some kind of "cache status report" and a short quote, but at least I write interesting info into the "status report" (like: condition of cache or log sheet, trackables, etc.)