I've been told by some current WG chairs that there's a tension between the goal of being a neutral party (for consensus leadership) and the goal of improving quality of the drafts. If there are organizational messages that discourage the chairs from using their technical acumen to ensure the review is well targeted and far-reaching enough (as is needed especially for problem drafts), this could account for some of the quality issues.
I'd like to see the WG chairs very technically empowered, while also trusted to be fair when they manage consensus. If they can't do both, it may be hard especially hard to guide/lead/manage the WG when dealing with drafts with quality problems.
Allison