I wasn't a fan of the whole idea of giving miners any special say on the issue. (Though it wasn't actually much of a vote, since miners could only confirm/reject P2SH.) Miners are basically employees of the network, and it should be the actions of users and businesses that influence what miners do, not the other way around. It would have been possible and better for users and businesses to (at a reasonable pace) force miners to accept the P2SH change.
I agree. Miners and pools have enough issues to worry about regarding planning and execution and securing coin for their investors. That said, they can become forces of manipulation if so inclined, by advocating for direct code changes to give themselves a competitive advantage or to harm another pool. A "you scratch my back, I'll scratch yours" situation between miners and developers will inevitably turn into a cartel.
Once we have crossed that line of developers directly beseeching miners to adopt their code, we've lost the plot.
Feedback systems and checks and balances are not contained within code, but this is not a drawback. The progression of conversation should be:
Users & Merchants (Idea) -> Developers -> Users & Merchants (Feedback) -> Miners & Pools
The extra check of Users & Merchants provides feedback relevant to adoption. No governing body is needed as long as everything is done publicly and the feedback cycle from Users & Merchants remains intact. Developers that do not allow sufficient time (at least months) for Users & Merchants to advocate on their behalf cannot be trusted. Client development can be slow for a reason, and vitriol is certainly expected and may even be encouraged and embraced as more rational ideas will always prevail over time. The more details we get, the clearer the picture can become till it is so clear that mining pools won't really have a choice once the implementation is put in place. Time is the developer's burden. It takes time to build a consensus absent proof of work, but it is still achievable.
At some point the developers will just have to just go for it and hope the miners fall in line or risk the user backlash.
I don't claim to know the proper governance in all cases, but I do believe what I outlined here is reasonable without having actual government. It should always be some form of a gamble for the developer, without the risk of fork, they could propose anything.