I'm a stay at home mom for the most part. I do work part time but only 1 day a week. I take care of our 1 yr old as well as all the cooking, household cleaning, etc.
You are not being unfair in your expectations at all. Unfortunately your actions at home just reinforce your wife's mindset. The amount that you are contributing to your households cleaning is much more than most men in your same situation. This is not meant as a negative comment in any way. It's just that most men who are gone for 13 hrs a day at work are usually exhausted by the time they get home at night (and rightfully so).
My husband has a similar schedule to the one you have. He leaves home around 6am and doesn't return in the evening til about 7pm. My husband has never done a single dish or load of laundry or cooked a meal since I married him. If I want him to take out the trash I make sure to pull the bag out of the trash can and set it by the front door and he'll take it out in the morning on his way out the door. He also deals with the joys of changing out the kitty boxes. This is only because he had to while I was pregnant and I just haven't "reinherited" the duty yet.
Somedays things do get hectic and I feel very overwhelmed. The job of "wife & mommy" never ends. Sometimes after a long day of fussy baby with yet another ear infection the last thing I want to hear is my husband complain about how long his day is as soon as he walks in the door. At least at that point, his day has ended unlike mine. My day starts when his does, yet doesn't end until my daughter falls asleep at 8pm AND I finish up dinner dishes, etc which usually pushes out my "day" to 9pm or so.
On particularly rough days (when either daughter or I don't feel well, etc), I do ask for a little bit of help. But, when I ask for "help" it's asking my husband to stop and pick up something for dinner on his way home from work so that I can avoid dinner dishes that night. I have also asked him to stop at the store on his way home to pick up some groceries. I do this only if I think of something I really need and he happens to be driving home at the time. I've never asked him to do any actual cooking or cleaning.
In my opinion, even though there's still a lot for me to do once hubby is home, I do not ask or pressure my husband to help me very much. This is because he gets home around 7pm and my daughter goes to bed at 8-8:30pm. I believe it's very important that he get to spend that time with her. My daughter loves it too. She eats dinner at 6 or 6:30 and is usually still in her high chair when my husband gets home. You should see the huge smile she gets on her face and the way she tries to break out of the chair when she sees him. She knows it's "daddy time" and she LOVES playing with him before she has to settle down for the night. If I were to pressure my husband into cooking dinner when he got home, I would be taking this precious daddy/daughter time away from my daughter, which isn't right. So, I let them have their time while I make dinner for hubby and I.
For me, I think that it's all about perception and choosing your battles wisely. I could easily start asking for help as soon as my husband walks in the door by claiming that I too was busy all day and that there is still more to do. But, I recognize the value in that time being spent as quality daddy / daughter time.
I also think carefully about choosing what areas to ask for help. It makes all the difference in the world. My husband seems more than happy to stop at the store on his way home. For me, it would be a hassle to load up the diaper bag, get kid ready, get out the door, get to the store, shop, etc. So if I can avoid a hassle and at the same time not inconvenience my husband too much, that's an optimal situation. Same goes for the trash. For whatever reason, hubby will not take the damn bag out of the trash can, and then take out the bag. I could either argue this point endlessly or just pull the bag out at night and set it by the front door. This takes me 5 seconds and he takes the bag out first thing in the morning on his way out the door. Instead of complaining about this, I just appreciate the fact that spending 5 seconds tying up the bag means I don't have to drag the stinky bag out myself.
I manage to care for my 12 month old, do all the cooking, clean the house, and even work a little bit. There's no reason your home should ever be a pigsty.
Good luck to you!