I think that's just a case of rose-tinted glasses... I played the original literally two weeks before BL2 came out, and at least as far as SMGs went it seemed like there were all of three different skins for them.
There's a pretty interesting discussion on the Gearbox forums about the weapon variety in the game. Seems Borderlands 2 has FAR less weapon variety than the first game.
I knew it felt that way but the numbers are surprising. Here's the important part.
Also it seems people are complaining that each manufacturers weapons look like each other instead of being made out of random parts... and that's just a silly, silly thing to complain about.
It's not rose-tinted glasses. Here's the data:
BORDERLANDS 1: 2,484,375 different weapon models.
BORDERLANDS 2: 61,875 different weapon models.
That's in terms of how the weapon looks, not the stats. If you include all stats then it looks like this:
BORDERLANDS 1: 17,750,000 possible combinations.
BORDERLANDS 2: 586,099 possible combinations.
These numbers may seem big anyway, but you do end up seeing a lot of the same weapon. Every Maliwan SMG looks basically the same just in different colours, every Jacobs pistol looks the same, and so on. The problem is that the weapon gimmicks play too much in to how the weapon performs. Every Torgue weapon is explosive, and explosive now has a very slow bullet velocity to the point where the weapons are not worth using. I know I'm not alone in just not using Torgue guns at all, they're all basically useless as far as I'm concerned.
I'm sure we've all found types of weapons we don't like. I also don't like Dahl sniper rifles or Jacobs assault rifles. Having to hammer the trigger for every shot is a pain, and it puts a physical restriction on the ROF that you can never overcome. It's not a problem if this is a random option on the gun, but this is tied to every single Jacobs assault rifle. In the first game, these weapon gimmicks were a random chance and not assigned to a manufacturer. You'd get mashers, shotguns that shot a smiley face, enormous magazine sizes, anarchy's (double bullet stream), It Shoots Rockets, thumpers, and it was randomly assigned. All this is now gone, and replaced with one gimmick per manufacturer. It severely reduces the variation in weapons.
Also, purple weapons of the same type all look similar. This is because they changed the algorithm that generates them. In BL1, the game would randomly pick from 7 different parts and calculate the colour/rarity based on which parts turn up. In BL2, the rarity of the weapon is chosen first, and it picks the best parts afterwards. The pool for purple parts is much much smaller so you end up with most of them looking the same because there is literally no opportunity for lesser parts to make it on to the gun like in the first game.
It's become pretty clear that the loot generation has taken a huge step back in this game. I hope it can be fixed in DLC but I feel like it's way too ingrained in the loot system of this game to be changed at this point.