It somewhat amuses me that someone that claims to have never visited the collection is comparing the opinions of those who *have* visited the collection to the uneducated rantings of flat-earthers

Despite my distinct distaste for the collection in question, I'd always recommend someone visit at least once in order to see and judge it for themselves.
I suspect the disparity between the overall opinion of the collection on Zoochat and the opinion held on Trip Advisor can be partially chalked up to two factors:
1) It's pretty much - in terms of large zoos - the "only game in town" as far as people in Cumbria and the northeast of England are concerned.
2) The general populace are unlikely to notice problematic elements such as carnivores being mixed with prey species, or trainlines crossing footpaths with no safety barriers.
Certainly, had my first visit come prior to my gaining a better understanding of various issues regarding health and safety, appropriate enclosure design and animal welfare, I might well have left with a better impression than the one I left with due to these two factors. In much the same way, I was enthralled by Highland Wildlife Park when I visited as a small child, even though looking back it was sorely lacking in certain facets of enclosure design and animal welfare. Fortunately, it has long since learned from these mistakes and is now, I believe, one of the best collections in the UK.
In other words, visit SLWAP before you dismiss the opinions of those who find issue with the collection as a "dark conspiracy" as you have elsewhere; you may still disagree with the complaints afterwards, but at least you will be able to do so from personal experience.