Unpopular Opinion: This is better than the graphic novel
Yes, it doesn't have the same impact as the graphic novel, and isn't as accomplished a piece of work. However, it's political perspective, which was attacked by Alan Moore, is less naïve and more relevant to the political reality. Remember, that Moore actually believed that Michael Foot, Britain's most unelectable political leader of the post-war period (and that includes even Jeremy Corbyn), was going to be elected in 1983.
Moore posited anarchy against fascism, but although it's a big shame that the film diluted the racial supremacist aspects of Norsefire (particularly in view of the Islamophobia that currently dominates the discourse in much of Europe and North America - although the reference to the Quran being outlawed was a great touch), the adaptation's liberal versus neo-conservative perspective is far more pertinent to a world in which corporations and neo-con warmongers pose a greater threat to the West than authoritarian/autocratic regimes.
That said, I can, sadly, imagine a Britain in which a party like UKIP came into power and sought to implement many of the social and economic policies satirised by the original graphic novels, but currently the real oppressors are not fascists but neo-cons/neo-liberals who implement illegal wars in the Middle East, keep the poor and working class in 'their place', and use propaganda, rather than a police state, to anesthetise the public into apathy.
I also like that Adam Sutler was not implied to be a closet homosexual in the film version, as Adam Susan was in the graphic novel. Instead the film's one closet gay character was the sympathetic, albeit tragic, Gordon Deitrich. The whole 'repressed homosexuality leads character to commit evil' trope, far from being a helpful and progressive plea to encourage gay people to come out, actually comes across as both sophomoric cod-psychology as well as ultimately homophobic and unsympathetic to the circumstances of many gay people. No gay person should be made to repress their sexuality. But the turmoil many repressed homosexuals feel is an awful cross to bear, but doesn't mean they will go on to become the embodiment of evil and cause others to suffer as they have, and to imply otherwise is in fact homophobic.