Fletcher has long been the goat in this situation ... and unjustly so. If interested, you need to read "Black Shoe Carrier Admiral: Frank Jack Fletcher at Coral Sea, Midway, and Guadalcanal published by the U.S. Naval Institute.
Admiral Fletcher was made a scapegoat for other admirals' mistakes, most notably Richmond Kelly Turner and Ernest King (my opinion
) , and then followed a generation of misinformed "historians" and Marines, embittered by the perceived "abandonment" by the Admiral at Guadalcanal.
This, by the way, is the same Admiral who went against all the odds at Coral Sea, Midway, and Eastern Solomons .... the same Admiral who's Air Groups killed 6 Japanese fleet carriers ... a record unmatched by any other U.S. admiral.
The Marine hatred and PR campaign against Admiral Fletcher stems from the failed relief of Wake --- it has nothing to do with Guadalcanal. And IF YOU STUDY the botched Wake relief effort ... once again, you will see that Admiral Fletcher --- a black shoe --- was the convenient fall-guy ....
I didn't want to get too much into the why Fletcher did it or whether he was right or not but I largely agree with you, I think the rest of his battle record speaks for itself. I am more a fan of Spruance, mainly because of Midway, but Fletcher was no slouch when it came to fighting.
On the whole, I think the 'Marines left on the beach with nothing' is more political than reality, it fits into their mystique better. This is in the same era when they were still fighting for their survival in the halls of Congress in the immediate post-war period and under the glare of a hostile President.
Fletcher did what he had to do, with the only US carriers left in the Pacific discretion was the better part of valor in this case, as evidenced by the battle later that night. Losing four cruisers is bad enough, losing the remaining US carriers would have been catastrophic.