Of course conservatism isn't very accepting of new ideas and viewpoints. Nothing political you can slap a label on, and that includes any of the left-wing varieties, is very accepting of new ideas and viewpoints. Otherwise, the label itself would be meaningless. (That's not to say the meanings of these political labels don't change at all, but it takes a hell of a long time.)
When individuals decide to accept new ideas and viewpoints, this creates conflict with the label they've chosen to apply to themselves. Enough new ideas, and they simply start call themselves something else. A conservative open to too many new ideas will stop calling themselves conservative, and a liberal open to too many new ideas will stop calling themselves liberal. This happens all the time, in both directions - it's the people that change, not the labels.
When individuals decide to accept new ideas and viewpoints, this creates conflict with the label they've chosen to apply to themselves. Enough new ideas, and they simply start call themselves something else. A conservative open to too many new ideas will stop calling themselves conservative, and a liberal open to too many new ideas will stop calling themselves liberal. This happens all the time, in both directions - it's the people that change, not the labels.