[nhaehnle]

Attribution of motive is never helpful or appropriate as part of a supposedly-technical discussion.

Disagree. Here's why: Other people's motives should never be a deciding factor in technical discussions. However, questioning participants' motives can be a very useful heuristic for deciding where to look for potential traps or previously unnoticed disadvantages of complicated proposals. Simply put, it's a heuristic that helps discover trojan horses.

The point is that technical discussions should be decided on technical merits, but it's important that everybody understands what those merits are. Looking into motives helps to achieve this understanding.

If it were, then maybe someone should also mention Fielding's own interest in enabling insertion of ads by proxies.

Absolutely. All those interests should be out in the open.