Thanks for this. We get the occasional vitriol-lined customer feedback. Intellectually, you have to let it roll off. Emotionally, it's obviously more challenging...
Without knowing the details, it's entirely possible that some of that vitriol from customers has real signal value for your business and is ignored at your peril.
Perhaps we should all watch Derek Siver's "A Real Person, A Lot Like You" on a regular basis.
https://vimeo.com/26110865