Actually, if you have interest in any subject other than English, that's what you should study. Getting a good-paying job in the field of 'English' is hard. Also, when you do, it sucks up a lot of your writing energy, sometimes leaving little leftover with which to work on your fiction.
But if you get a job in another field, as Stacia said, it both lets you use your writing creativity for yourself AND (depending on the job) lets the back of your mind ruminate on your own stuff. Also, it can give you more 'life experience' on which to draw for your fiction, depending on the career path you end up on. (For example, anthropology is a great line of work for fantasy writers.)
That said, I'm a tech writer, and I LOVE the work. It's fantastic to have a well-paid job doing what I like best: mucking about with words all day. It's a good career for someone who wants to write. The only problem with it is what I mentioned above. After sitting in front of a computer all day writing, it's hard to go home and write some more. I have strategies to work around this problem, such as not actually writing at my computer at home: I write in longhand and use an AlphaSmart; but it IS still a problem.
And I wonder if I'd get more fiction writing done if I'd found a good career doing something -- anything -- else. Too late now, but I do wonder.
So there you go....a vote both pro and con for majoring in English!
Oh, another thing. DON'T major in a subject (such as business or computer science)
only because you think it'll get you a good job later. If you decide to major in Something Else and minor in English, make sure the Something Else is also Something You're Interested In, otherwise, studying will be a drag and it'll just be a waste of time. So if you're actually interested in business or computer science, great; but if not, don't major in them.
Oh, and one
more thing. There's also the old joke: What's the most common thing someone who majored in English says? 'Do you want fries with that?'