Aside from the one case of an early Vampire class that never saw publication, Vampire was a race or a race template. And it always worked better in D&D as a template, because it allowed flexibility in what a vampire could be. Some vampires in D&Ds other than 4e were fighters, others mages, and such.
In 4e there was a vampire race (the Vyrokola), a vampire multiclass feat, and a vampire class. Some vampires in 4e were fighters, others mages, others thieves, one of my favourite was a warforged vampire brawler fighter called Iron Maiden. The vampire class was for hammer horror vampires. 4e in that way had more not less versatile vampires than other versions of D&D because having one option doesn't prevent other options being present.
Vampire was more Tier 5. Here is the definition of Tier 5:
"Capable of doing only one thing, and not necessarily all that well, or so unfocused that they have trouble mastering anything, and in many types of encounters the character cannot contribute. In some cases, can do one thing very well, but that one thing is very often not needed. "
Fits the 4e Vampire to a tee, I'd say.
Here's the definition of Tier 4
Capable of doing one thing quite well, but often useless when encounters require other areas of expertise, or capable of doing many things to a reasonable degree of competence without truly shining. Rarely has any abilities that can outright handle an encounter unless that encounter plays directly to the class's main strength.
And "Capable of doing many things to a reasonable degree of competence without truly shining" is the textbook issue with the vampire. They're mediocre strikers but still contribute to combat. High CHA and utility powers that help charisma help them contribute to social situations. They're DEX based with a skill list that includes stealth and thievery - they can contribute to sneaking and exploration situations. They also can turn into bats and get a climb speed further enabling them to contribute to sneaking and exploration. Oh, and they can pull off ridiculous feats of strength once per encounter - and the feats of strength and the climb speed are in addition to rather than instead of normal encounter powers. While the ability to turn into a tiny bat every encounter is a far more versatile utility power than most classes get at level 6.
That's all three pillars they hit (social, exploration, and combat) so the Tier 5 "in many types of encounters the character cannot contribute" is arrant nonsense. There's just no area where they shine - but they can contribute in all the pillars, with intentional inherent synergy in all of them.
What they are is too weak to be effective
strikers - their combat contribution lacks multiattacks. But they can outdamage most leaders; their contribution isn't nothing in combat. They just don't get to truly shine there.
The Vampire was split along both of those lines, actually. Most DEX powers were weapon-based and most CHA powers implement-based.
No it wasn't. I have Heroes of Shadow open in front of me and double checked every vampire Dex-based attack. You are simply wrong in your assertions.
Every single one of these classes had party compositions where they could be placed in without incident. Just as many AD&D parties with Paladins had them without incident as not. Same with the 2e Thief. 1e Barbarian was OK if nobody at the table was a Magic-User. And Templar was there for Dark Sun parties who wanted to be evil.
I wholly reject the premise that any of these classes belong on any worst list when they all had situations they could cooperate in well enough, and none of them were mechanically inept.
So a class that causes party tension unless you build the entire party around it is fine. Why then is a mechanically weak class that you can build the entire party to match a problem?
I'd argue the 3.0 Ranger and the 3.0 and 3.5 Paladin also mechanically did not work.
Nah. They just sucked.
3e Monk was pretty bad. But still better than the Ranger in 3.0 and the Paladin in both 3e revisions.
That's ... open to opinion on the Paladin. The tier system puts the Paladin alongside the Fighter on "Could easily be considered tier 4" and the Monk a very solid tier 5. For that matter given how useless the monk abilities are and that the ranger works up to 4th level spells the 3.0 ranger vs the 3.0 monk was open to question.
Thief skills were not situational. There was always a use for opening locks and disabling traps in evey AD&D game I've ever played.
Sure ... because the adventures were deliberately written that way. But you don't need disable traps to disable a trap. Also the 1e thief only hit 50% in find/remove traps at level 7.
3e Rogues had their issues with Sneak Attack-immune enemies but was still one of the better martials. And all martials were obsoleted by full casters, so the Rogue was in the same boat there.
The problem with the 3.X rogue was that sneak attack was such a binary thing and could be obsoleted by entire adventures because creatures of the same type tend to gather together. Going up against a necromancer and their undead minions? Guess the Rogue's just an overpaid Expert. Going up against a clockwork army? That should be a party for the rogue - but it isn't. Going up against Fangorn's Wood? Guess the rogue stays back in the town. Those oozes split and split again? The rogue's not helping.