Notability alone shouldn't definitively authorize quashing an article at AfD. It especially should not suffice when the article is well-written and compliant with all other policies and guidelines. No other policy (much less guideline) is so absolute, but bureaucratic creep has overinflated notability.
Keeping non-notable articles does not tarnish Wikipedia. Their existence expands the pool of information recorded on Wikipedia, the most comprehensive encyclopedia ever written. The encyclopedia can continue growing even when "notable" topics are largely covered. New users are welcomed, as they often begin collaborating by adding new articles. Existing editors are invigorated, as they must resort to increasingly obscure topics to expand the encyclopedia.
Meanwhile, wanton deletion of non-notable but otherwise solid articles is destructive. It drives away the involved editors, destroys information, and limits the encyclopedia's scope. If someone cares enough to write an article, someone else probably cares enough to read it and marvel at Wikipedia's depth.
Notability remains an important guideline. It can and should be part of a comprehensive keep/delete argument. Demonstrating notability advocates for keeping articles that may have other problems. On the other hand, failing notability, like any other guideline, strengthens a deletion argument. But non-notability alone does not justify deletion. The same is true for articles that do not show verifiability, neutrality, independent research, or a slew of other qualities required by policies or guidelines.
Consider the WP:BLP policy: biographies of living persons with negative information are not prohibited per se, but they are held to a higher standard. Such should be the case with non-notable articles. As topics become less notable, they must more definitively meet Wikipedia's other policies and guidelines.