I've been wanting to write this for a while, but I've been mostly AFK from the wiki the last couple months. The truth is that, for me, BL2 was a huge disapointment. This is my opinion, and you are free to not relate, but I really hate this game, which makes trying to contribute to the wiki harder.
BL1 was my favorite game ever
I like to think of BL1 like I did Diablo 1: Both are my favorite games ever. They are rather simple, the *actual* gameplay is fun (*really* fun). You don't need to worry too much about end game, cookie cutting or what not. Getting loot is fun, but the core fun is *Finding* the loot.
I hate BL2
I'll start with the two most important points, then nitpick at the last 2 points:
The gun play is boring
EVERYTHING in BL2 is gimmicky. In BL1, the guns where fun to use, felt like they packed a punch, and behaved normally. Each manufacturer had it's character, but not in that over the line kind of way. In BL2, all the guns are all weird fancy things. They feel like they'll snap in your hands, or who knows what. Where are my machine guns?
As for the guns, they're mostly all the same anyways. Seriously, they mostly all have the same accuracy, and not very varying fire rates. While there are more "types" to chose from, I feel there is much less variety in terms of stats for a given weapon type.
The game is about getting the *Best* loot
In BL1, it didn't matter much *which* gun you had. If it was purple, it was mostly good. Sure, the Legendary's where great, but not game changing great or anything. Finding good loot was fun, because good loot was good. In BL2, it feels it's not about *finding* the loot, but about needing to absolutely have this weapon or that shield to be the best player possible (think The Bee, the Infinity, Conference Call etc).
It's Diablo 2 all over again (I hated that game).
In a word, the interest is shifted from "playing to find loot because it's fun", to "loot so you can play, because the game is about having the best loot".
Exponential growth means your guns suck
The exponential growth scheme means the game doesn't start until you are level 50. The rest of the time, you are using crap guns, because the instant you gain a level, a crap gun will out rank a good gun two levels lower.
In BL1, you could find a single gun that could carry you 20 levels. It was really a golden find, and finding such guns was a thrilling experience. Who doesn't remember that Jackobs 2 shot masher they found, or that killer matador, or that awesome Massacre.
In BL2, not so much: The guns are mostly throw away until you reach level 50, and then you can start looking for good stuff.
The characters are fucking boring
They all feel like shadows of their former selves, with the souls gone. They are cute and all, but it just isn't the same. I fucking loved Scooter and Tannis in BL1: They had character and soul, and originality. But in BL2, They're both just meh.
As polished as BL2 is, I feel it has lost the magic of what made BL1 so great. I've long uninstalled it and moved on, and even re-created a new game in BL1 to see if my feelings were not "nostalgia" driven.
They aren't. At the end of the day, when I'm playing BL1, I'm having fun and enjoying the experience. BL2, well, I'm just not enjoying it :/
Feel free to disagree, but I wanted to get it off my chest...