Well, there are many reasons but firstly, both these constituencies are safe seats for Labour in Oxford and for the Conservatives in Witney. Due to our out-of-date first past the post system, many people quite rightly feel that their vote doesn't count and I am one of those people. I get fed up with voting for candidates and parties which can get millions of other votes but sometimes only a single MP. It's just not fair and it makes a fudge from Tory Blue to Tory apologist Red governments. It also works against younger people, who tend to be even more poorly represented as they tend to vote moreso e.g. for the likes of Green party or other smaller parties.
Here is a taste below of why the people of Oxford/Witney need a Mad Hatter.