By what standard? If its just your personal subjective interpretation, it just means that someone has an opportunity to steal you away as a consumer.
If there really is a broadly-shared, unmet need among Google's current consumer base that is both technically feasible to address and easier to address in a new platform (either technically or for social -- e.g., for organizational inertia reasons) than it would be for Google to implement in their own services, then, yes, Google is ripe for disruption.
But lots of people (including people selling rival search engines sponsored by deep pockets rivals) have been saying that since shortly after Google became the dominant search engine, so unless you are going to spend the effort to either make a credible case as to the specific unmet need that supports your claim that Google is ripe for disruption (and "I would posit that Google isn't doing well in search from a quality perspective" is the polar opposite of "specific" here) or, better yet, show me the MVP of your product that not only identifies the unmet need but demonstrates the feasibility of meeting it, I don't see much substance to your position.
First: That doesn't specifically identify a broadly-shared need among Google's existing user base that Google isn't meeting.
Second, when I do a search for either of those I get personal blogs and/or fan sites on the first page. So, unless your problem is that that shouldn't be the case, I think the perceived situation you were obliquely referencing isn't even accurate.
That would only be true if there was a search engine with better quality results.
I agree that Google has dropped it's quality (compared to itself) but it's still better than anything else.
Reality also is that there is often a declining marginal value in additional investments in the same area once you are already doing very well in that area, and that the marginal profit from doing something else mediocre may be greater than the marginal profit from doing the existing thing a tiny bit better.
And lots of Google's experiments that are outside of what are understood to be its core strengths when they are introduced end up as things that are at the top of their field: Gmail and Chrome, for instance, weren't at the center of what Google did when they were introduced.