It's really not and I couldn't disagree with this idea more if I tried. The vampire being so on rails makes it one of the most bland and uninteresting classes in 4E. There will be no diversity practically between any two players and that's just boring.
Each person has their own preferences, of course. However, I can tell you from experience that sometimes less choice IS better.
Most classes in D&D/1e/2e had virtually no choices at all at first level. Basically your only choice was what weapon you'd use and your character's personality. But for most people, that was enough to differentiate 2 players. And most people played only one D&D game that would go on for a year or two before switching characters. So, you'd see a maximum of 2 fighters in that time.
Back when we played 2e, it was understood that 2 players of any one class were going to be identical. So, if you didn't want to be the same as someone else, you chose a class no one else was playing. Even classes that had some choice ended up pretty much identical. There were only so many good 1st level spells, so every wizard had some variation on the same spells.
When we switched to 3e, there was a LOT more choice. Between feats, multiclassing each time you leveled, many more books coming out, and so on....No two characters were exactly the same. But with the benefit that brought, it also brought just as many problems.
It wasn't until recently that I realized how much I missed a LACK of options. The simple fact remains that more options means more that all the members of the group have to know and keep track of(especially the DM), and it means the more opportunity there is for power gaming and min-maxing. More choices=more broken. It's that simple.
That's why my game recently switched to essentials only. So far, it has caused the players in the game to concentrate more on what's going on IN the game and less on spending weeks scouring message boards and books looking for the perfect power to take each time they level.