Zerodrone, I understand what you're saying, but remember that QC is how Jeph earns his living. Given his apparent success with the specific QC ethos (for lack of a better term) and the merchandise based on it (with the merch ideas coming directly from the strip on an ongoing basis), it makes perfect sense for him to continue the strip as long as possible. Sure, he could wrap it up in a couple of months and do something else, but as the saying goes, "A bird in the hand is worth two in the bush." If he moved on to another project, with or without fast-paced storytelling, there's no guarantee people would like it as much, and while he might elect to continue doing that other project just for the enjoyment, he might not be able to support himself with it.
As for the argument that Jeph should have "some bigger plan for his life," that QC should not be "the only thing he does with his talent"...with respect, I don't think it's anyone's place to say what a creator should or shouldn't be doing with his life. If Jeph feels that QC is fulfilling his potential and is making his life enjoyable and meaningful (while also earning him a living), more power to him.
I'll close with this
Something Positive strip that says it all.