Improvement of track and signalling should not impact negatively upon residential, how many were laid pre Beeching and not modernised since?
A line near me the Halton Curve was re-opened not so long ago after years of campaigning. When they did actually open it, they only relayed one track.
That therefore is the problem. The U.K. opening a single track for what it sees is sufficient. Rather then two, and allowing the line and therefore numbers to mature and grow. I have no doubt more campaigning will happen when more capacity is needed.