From me at least... I am strongly frustrated by authors who do not use a proofreader. I also want all of my readers of all of my works to know that I strongly appreciate any suggestions that may be made with regard to improving my work.
I know I have stalled work, and I know that what I've called flash stories are closer to scenes that aren't really stories. I do ask you indulgence there as I try to develop my ability to know what constitutes a true story (not a story that is true but one that is complete) when I'm the author rather than the reader.
Anyway, if I run into a story that stays (or is published) with a lack of proofreading I will mark it lower than I would otherwise, simply because in the end, lack of proofreading at a site like this with a number of volunteer proofreaders available is laziness in my mind.
And yes I do know I've been somewhat lazy with what I've put up lately, however, I do solicit any suggested improvements to any and all of my stories once more.