Self-publishing

I have been reading various justifications regarding self-publishing recently, written by self-published authors. The points I see made most often are: (1) Self-publishing does not have to mean lack of literary quality, because authors who strive for excellence often self publish. I will admit this is true. (2) Self-publishing is a viable option in the face of increasingly picky agents and publishers. I will agree that agents and publishers are becoming more selective.

I have quibbles, however. (1) As a reader, I can trust that traditional publishing guarantees that I'm not going to pay good money for absolute dreck, whereas with self-publishing there's no artistic winnowing---it's a crap shoot. (2) As a writer, I ask myself, if no literary professional thinks my book is good enough to invest money in, why would I, a literary amateur, invest in its publication?