There are 2 statements in this.
1. Anand was never a world champion
2. Kramnik is the (world champion)
which do u find disputable?
Both are opinions, therefore disputable.
The dispute falls into two categories at least.
1. Unfair selection process/system. (short time controls, hand-picking, knock-outs with insufficient chances etc.). The title is dispute.
2. Lack of participation (due to split, contractual obligations, uncertainities, venue etc.) The title is dispute as well.
Should the dispute be purely on the grounds of lack of participation, a unification would have rectified it and made the title an undisputable one. That is not the case here.
So, bottomline is:
1. Either consider no one champion. OR
2. Consider all champions world champions. After all it is not entirely their fault.
I rest my case.