I think it also has to do with where they were in life when they stopped aging. Rumple was already a married, middle age man with a child. I think a lot of his maturity and wisdom came from those life experiences. Neal may have had a child but he didn't find out until the last year or two of his life. He made a lot of selfish choices as an adult without really growing.
Hook seems to have done more growing up then Neal and has become progressively more mature over time, from his position in the Navy to Pirate to Pirate wanting revenge to a man wanting love. The posts above did a good job going over the differences in Hook's love with Milah to his love for Emma whereas Neal didn't treat the relationships he had on screen with much respect.
I thought Wendy had spent approx. a century in Neverland, Is that not correct? She went after Baelfire and was then caught. I just assumed that when Bae got to England it was late 1800s or early 1900s because of costumes and sets. The timelines are all over the place that I never know what is going on and where lol.
Good point. I think both Daniel and Milah were real love or first loves (don't know if Milah was Hooks's first love) of their respective partners but not necessarily a true love. Daniel and Milah were both tragically taken away and I think that changes how that love is viewed to the surviving couple member, especially to Regina. When Daniel was murdered Regina was so in love with him but had they been allowed to be together then the relationship could have fizzled out in 6 months like first, young loves often due. Regina wouldn't have blamed Snow for ruining her life has they broken up and she could have moved on to a healthy, happy relationship.