It's here in this thread. Some people have chosen to ignore it completely. Take Cuddles for instance. I gave links to bona fide examples of shot and caught alien cats that were at large in the British countryside. Cuddles ignores this and then proceeds to ask me if the photos William Parcher poster was the only evidence there is?
As many people have pointed out, no-one is arguing that there have never been big cats loose in Britain, what we are saying is that there is no evidence that there are currently any big cats loose in Britain. All the photos I have seen are at best inconclusive and at worst very obviuosly not alien cats. Just because lots of people claim to have seen something does not make it so. Just because lots of people have blurry photos does not mean they saw anything unsual. The reason everyone is arguing against you is because you are simply trying to argue against a straw man that none of us care about. If you want a to have a reasoned discussion on the current existence of alien cats you need to provide your evidence that they exist. If you simply keep saying that a few have existed in the past and that therefore all anecdotes should be considered good evidence, we will carry on not taking you seriously.
The Loch Ness Monster is even funnier because the legends are hundreds of years old, older than any animal known. To postulate that there is anything unusual in the lake that has given rise to the legend requires an entirely new creature that has not been recorded before, whether this is a single long-lived creature or a breeding population of something. It is worth bearing in mind that giant eels only seem to be referenced on cryptozoology sites, and appear to have no basis in scientific fact. As such, claiming that the monster could be sightings of giant eels is no less silly than claiming it could be a dinosaur. In addition, the fact that despite many claimed sightings there is not a single good photo or specimen to show that there is anything in the loch means that you are really looking for an explanation for something that probably isn't there. This is very similar to "researchers" trying to find an explanation for telepathy, despite there being no evidence it actually happens in the first place.