Delta is a legacy airline which means perception is negative due to the industry group it is in. I don't see any other airlines listed of any type.
And sometimes you have to ask, "so who really cares?" and "do the measurements you make really translate into anything that matters?" when you see surveys like this.
JC Penney has had real strategic and financial issues but Philip Morris is a stable company that just happens to produce products that are not well-perceived in most of the western world. And then you have NYC trying to limit the portion sizes of soft drinks produced by the top two rated companies.
IOW, so what.
Meanwhile, DL's market cap is still the highest airline in the Americas and one of the highest in the world and DL's customer service metrics are above average even when the low fare carriers are included.