i agree with what you said, bullet catcher, though i dislike your examples.
those bands you named, they aren't exactly... well they're not being let on metal-archives because its been established that they're not metal. I figued i'd use a backing for my opinion because im not one to bash on things just because i don't like them heh though thats exactly what i'm doing now i guess. I still don't think dillenger comes from metal, its more of a technical/prog/hardcore weaving.
Just think about how metal came about though, i mean we've got rock 'n roll to start us off yeilding to glam and thrash, thrash went into death metal and glam went into power metal and thankfully glams gone hah, and death metal turned into black metal (an example of this slow change could be seen through the works of darkthrone -- soulside journey was death metal, and say... Mayhem, the album deathcrush was death metal influenced) and black metal brought on Viking Metal and what not.
To recap, cross breeding is how genres become established - i think its healthy and "43% burnt" was the only dillenger escape plan song i could ever even half-like