I really don't know what you mean by this. Div OS1 had some of the best mechanical polish of any crpg I've ever played. I can't even find a game that holds a candle to it. So it make perfect sense why people are disappointed that Div OS2 was watered down significantly.
Some complaints I heard:
Stealing and crafting should have been more interesting, self-made items are too powerful.
Sneaking is almost always worse than invisibility skills.
Bartering and lucky charm have very little effects, and it's tedious to switch to your looter for looting or move items and money to your barterer.
Persuading has a rock paper scissor mini-game, annoying if the player really wants a certain outcome, and it doesn't scale well, 11 points for each win is no different than 6.
Item repairing is really tedious.
Traits pressure the player to make certain role-playing choices for character builds.
In the vanilla version, breaking a chest would lead to content loss, why they removed that in EE?
Strength/dexterity/intelligence are bland and discourage hybrid builds, though not completely invalidate them. Perception is too weak.
Talents are quite unbalanced, Hyperopia actually lead to less accuracy in long range.
Too much hard CC skills, grenades, arrows. Smoke is too effective against long range enemies.
Lack of synergies between earth-fire and water-air. It would be great if steam cloud is more useful, for example.