It should be noted that there is a difference between dog lovers and responsible owners.

I know people with adopted dogs, and yet do absolute shit to do any sort of behavioral or obedience training, and chalk it up to the dog's prior history or mental issues.

It's a load of crap.

A family member (that I lived with) had a Pomeranian that would want to attack me every time I left the room. She always put the blame on the dog, his history, etc., and never took the time to train him. The worst part is that I couldn't do anything to help the situation - just as it is uncouth to train someones child, it isn't my role to train their dog. Now, she wants to spend a couple thousand to correct his behavior. Odds are, the dog is going to come home, and then relapse into all of his old habits because I know that she won't do anything to reprimand or reinforce the dog's behavior.

Before you think I'm barking out fluff, I've had several dogs in my life, the most former a Chesapeake/Lab that I trained to do a bunch of tricks, my current an ex-racer greyhound. The adoption agency warned me that they're nearly impossible to train. Now he knows how to sit, shake, lay down, and I'm working on fake sleeping. Although he is a bit stubborn, he knows "relax!", "go to bed" and other behavior-oriented commands. Greyhound owners are always shocked that he knows any tricks, follows commands, doesn't chew on furniture, and doesn't kill our cat, but I'm confident that it's because I took the time and effort to make sure he wouldn't get into trouble.

If you're a dog owner or plan on getting a dog in the future, please don't make excuses and take care of your pet. They'll reward your kindness ten-fold and everyone will be much happier in the end.