John did try to give them a normal life. And the dependency wasn’t just because of John saying “Look out for Sammy”. I think those two points can be demonstrated perfectly well here in this quote from John Winchester’s journal (which is an authorized book):
"Dean still hardly talks. I try to make small talk, or ask him if he wants to throw the baseball around. Anything to make him feel like a normal kid again. He never budges from my side — or from his brother. Every morning when I wake up, Dean is inside the crib, arms wrapped around baby Sam. Like he’s trying to protect him from whatever is out there in the night. "
Mary’s death and the fire started Dean’s dependency on Sam. John’s orders weren’t the whole reason Sam became dependent.
John wasn’t a good father figure. No. But he was a father who tried his best. And I know people don’t like when JW fans say that, so sorry. But it’s true.
And if Dean feels like he’s not good enough because of John, it’s because he read things wrong. Sam thought Dean was John’s favorite. Dean thought Sam was John’s favorite. The reason for Dean’s low self esteem was because he compared himself to Sam when it came to John. Also, I believe there’s got to be other things that caused his low self esteem. I’m pretty sure this paragraph is more headcanon than actual canon, but saying John is the whole cause of Dean’s self hatred is also headcanon.