themaninthejar - 11:23 am on May 29, 2012 (gmt 0)
Could it be a combination of this, KW packed description meta and sitewide anchor text all just adding up to over optimisation.
I'm focussing on the onsite keyword density primarily (now paused waiting for WMT to catch up and give me an updated Content Keyword report). I'm waiting for more evidence that backlinks are a big enough part of the pie to merit my concern, although you can't ignore the emails many people have received telling them about "possibly artificial or unnatural links pointing to your site that could be intended to manipulate PageRank". I have not received such an email, but I'm unsure if its absence means my backlinks are all safe.
My thinking is that any on-site de-optimising work I do has the added benefit of making the site slicker, faster and improving visitor experience slightly. Any off-site de-linking I do is possibly time down the drain with no added side-effect benefits.
Also onsite work can be reinstated (in part) more easily if appropriate in the future.