First, I thought BRD and MCH are different.
But in fact, they share the same mechanics for the most part. Many classes share the same mechanics, but BRD and MCH share the most.

Balancing or not, there would be a better way to keep both sides satisfied.
An example:

Machinist:
- No Changes
-> Range-DPS with fast casts and high burst

Bard:
- Remove Wanderers Menuett (but keep skills from WM)
- Add piercing damage-buff
- Increase potency on skills, when both DoTs are up
-> Range-DPS with higher mobility

I think, that most people stop playing Bard because of WM. It just changed the movement of this class from "agile" into "slow".