People, I think, are generally used to a high degree of movement in cartoons, whereas anime is a minimum animation medium so that is one reason they could be sceptical.
The other reason is the obvious association of animated productions with a very young audience.
The poor foreign and domestic marketing strategies and the inadequacy of the market model. (probably outwith the scope of your research [UK focus])
Lack of expectation. Licencing companies don't recognise anime as a stable source of income once invested into.
The subcultures and consumer classes existent in the domestic and foreign markets don't overlap. Even the self-proclaimed otaku of sites such as Anime UK News, etc., are overshadowed by the actual Japanese otaku who keep the system running (and force studies to shower the world with moe vomit). The average UK fan is not as dedicated as his or her Japanese counter-part.
Easy categorisation of western media makes it hard for most people to digest the tints and shades of anime. Many are unwilling to search for "personal favourites". Anime is not merely action, crime, sci-fi, fantasy and drama, but often a mixture of these and many other elements. My personal opinion is that some people find many pairings rather unorthodox and unpleasant, not to mention the bold deviations from history/mythology/theology/philosophy/etc. (Saber = Arthus equivalent, but female, for example)
In fact, these are just a few examples. In anime, of course, everything is possible, and some are very conservative. My opinion is that anime has much more potential than any other medium (arguably CGI has loads too), because of the low production costs and the malleability of the medium. Plant the thought in the countless classy metrosexuals that roam the streets that anime is associated with their refined subculture and the UK will become the Eden of Anime.
