I have absolutely nothing to go by, no evidence, nothing - it's just a gnawing, gut-level feeling coupled with the fact that I'm way on the conservative side to begin with - but I'm cutting way back on keywords and hyphens in URLs.
On a new site, if for example I've got winter widgets and summer widgets, instead of using directories and filenames with full hyphenated phrases, I'm doing instead
Even where it could have been /winter-widgets/mens-wool-winter-widgets.html, etc.
I have to repeat and stress that I've got nothing whatsoever substantial to base this on. I figure I can always change pages around some and change a site structure and page naming later on if I decide to, and I've just gotten a little squeamish about this.
A load of hyphens have just begun to make me a bit uncomfortable, so I'm going by my feelings and doing what I'm more comfortable with for now. I started out doing all this by "instinct" at the beginning, and I've grown to trust it more over time. Things that have started to look overly seo'd and a bit spammy to me, even when I do them myself, might also look that way to others if there's ever a hand check. And I've not done badly at all with what's been kept fairly understated.
I wouldn't tell someone else not to, it's just my personal feeling and choice right now.
I have to add that I do have pages doing just fine with Ink that do have hyphens in the directory and filenames - but the sites don't have hyphens in the domain name also.