Why does he hate his harness?

So my dog hates his harness. Or more specifically, he doesn't want it put on him - once it's on he's fine and happy.

Basically, when I figure it's time to go for a walk, I go get harness & leash. Dog realizes this and goes and positions himself around the other side of the dining room table where he's figured out it's easy to avoid me by just keeping the table between us. He won't listen to sit commands, stay commands or anything else - it's basically an attempt to keep as far away from me as possible.

Eventually, I manage to herd him somewhere where I can get ahold of him and the harness on him (it's an Easy-Walk harness by the way). He turns his head to avoid it, but eventually I get the harness on. He then goes over to the door where he's willing to wait/sit etc. for me to attach the leash so we can go out.

This is really annoying. I thought dogs were supposed to be doing back flips out of excitement when it was time for a walk.

We introduced the harness with lots of treats. We treat him when the harness gets put on. He doesn't ever go outside without the harness, so you'd figure I've covered all the positive reinforcement bases for this thing. Yet he tries to avoid it whenever it comes out. And, once it's on - all is well.

Any suggestions on how to fix this neurosis?