Normally, I wouldn't mind bastardizations and tweaks to the formula. I'm not a "grog" in that sense. But this is supposed to be a spiritual successor to a series of games that did things in particular way. This game deviates from them where it's completely unnecessary.
It is an absolute minority of players who want the static, choiceless level up system from AD&D and the IE-games. Making no choices when you level up is considered fun only by the smallest crowd of set-in-their-way-fans. While this is 100% OK of course, I think making character development less interesting is a prime example of paying misunderstood homage to the older games.
We expect Obsidian to take everything that worked from the IE games and re-implement it. While there are certainly points in the game where Obs can be criticized for not doing this (see the discussion on engagement, attributes and UI on the last couple of pages), character development certainly isn't one of them. I think if you want to name a spot where they really dropped the ball, it's multiclassing.
That's also where your "strong archetype" falls apart a little. The dual/multiclassing of the old IE games remains one of the sole very fun customization options in those games, and those broke completely with the stock and static classes the game otherwise presented.
Also note that one of the prime criticisms of the Enhanced Editions was that they did not take the opportunity to update the old IE-games to improved systems with more interesting character customization.