If Yahoo is to make a comeback, they need the types that have been in charge of Flickr (or so the community's reasoning goes). Flickr is the one thing we like that Yahoo's doing (well, maybe add Delicious in there too). And yet Yahoo is letting those properties languish and the talent that works on those properties leave. Sure, Google loses talent, but generally speaking I don't find certain Google properties to have an interface that is so markedly terrible compared to other Google properties. Our community looks at Google's ventures and while they might not understand social, we see that there's a decent consistency of engineering. However, we do look at Yahoo's different properties and many feel like they came from a different company - partly because Yahoo bought their way into Delicious, Flickr, and Upcoming (yea, I added another that I've almost never used).
Imagine that Google had bought YouTube and YouTube's interface and engineering was just so markedly better (to you) than the rest of Google's properties. Then the employees who created this, in your view, superior product started leaving constantly. You'd think: c'mon Google, you bought yourself into the good stuff and we want to those engineers bring that good stuff to the rest of your line, not leave with their products languishing!
People move around, but I think many of us feel that Yahoo has markedly varying quality depending on the division of the company. It might not have any actual significance and engineers might not be leaving those divisions more often than other divisions, but it does have an emotional significance for our community. Many thought that Flickr heralded a new Yahoo. It makes it feel like Yahoo doesn't get where it's gone wrong (in our ultra-hip, we know what's best not some CEO the investors have hired, why isn't the world listening to me as I type away at my keyboard on the internets way).
/Apologies for speaking for everyone; it's more just a theory.