You should finish that dissertation because:
1) You have already successfully jumped through so many hoops to get to the point of the big D that you ought to jump through that last one.
You will learn something.
Something insightful - about your ideas. Did they pan out? You want to find out, don't you?
You *can* do it.
No matter how pathetic and inadequate you feel about your research or your position in academia (graduate school is a pride swallowing, belittling, gut-wrenching, losing all sanity venture) you are good enough, you are smart enough, and god dammit you are worth it.
Take it from someone who has finished the Pretty Huge Document:
It is way more satisfying to have a Pretty Huge Degree than to be All But Done.
No one likes leaving behind lose ends. Tie 'em up and get the heck out of there. ABD is All But Dungeon if you don't get your butt out of there.
When you're done, you get to be called DOCTOR.
People respect that credential. You're 90% of the way there, why not do the last 10%? It will be worth it to hear your dad say "What's up Doc" when you call.
You get to wear the garb.
It is freaking cool to wear the doofy hat and walk around like a dork on the day of the hooding ceremony. When I graduated, I got to wear a kick ass costume and even had the chance to be hooded by a President of the United States so I wanted to finish! Who wouldn't be motivated to finish just to potentially get goosed on stage by Bill? We all have our light at the end of the tunnel ;-2 You know what your dream is. Chase it.
It doesn't really take that much effort.
You have been percolating the ideas and preparing for years. Once you sit down to actually write it, you'll find that it gets easier and easier the more you have written. I wrote mine in ONE MONTH. I wrote the preliminary document that I put to my committee in a month, they approved it, I started collecting data, and then when I had processed the data, I found that I wrote the results up and the rest of my dissertation in ONE MONTH. That is all that is standing between you and DONE. One measly month. Anyone could do that.
You *can* do it.
That bears repeating. The impostor syndrome virus lurks around academic halls, but you are immune to it. That is, once you finish your dissertation. You will no longer feel like a loser. When your students don't give you the respect they give to "real" profs, you can flaunt the degree in their face. You can make them call you Doctor. It changes everything. Your colleagues will know you had the grit to finish, and they will want to collaborate with you more now than ever.
[edited to add]:
When you get your first request for a pre-print, you will hit the roof and then you'll want to revise and submit your dissertation for publication because it is way better than your earlier work!