The reason to limit stats is because players can literally focus too much on a particular Ability score and make them so tough it's imbalanced.
Yeah, I suppose I never gelled with raising core stats when leveling up. I prefered BG1&2/Pillars approach when you define stats during creation and that is that - that's who the character is. Their progression is achieved through different means, and stats stay the same.
I just don't find stat increase to be a mechanically interesting choice. When creating characters you will always favour about two skills. When given a choice to increase skills you will focus on those skills as those are important to you. I found it less offensive in Pathfinder when it was just something I would do, but I don't like how it is handles in 5e.
