But what you forgot to mention is, that only 30 people play prevoker, so basically ALL of them are above 2400?!
I hope this little fake news showed you how important context is. Pure numbers are meaningless! Some better context, data based on check-pvp.fr:
| spec | > 1600 cr | > 2400 cr | ratio in ‰ |
|---|---|---|---|
| Disc | 5617 | 39 | 6.943 |
| MW | 4428 | 114 | 25.745 |
| Rdruid | 3079 | 150 | 48.717 |
| Hpala | 5965 | 188 | 31.517 |
| Hpriest | 4003 | 57 | 14.239 |
| Rshaman | 3132 | 44 | 14.049 |
| Prevoker | 1599 | 30 | 18.762 |
That leads us to the conclusion, that prevoker isn’t as bad as you are trying to make it. It is just not as popular.
The most popular but worst healer by far is disc. The most broken healer by far is Rdruid!
MW seems to be in a balanced spot. Upper midfield, means high to mid A tier.