I do think that if TOCs do not wish to employ conductors or station staff, anywhere on a line, then it is inevitable that the takings will be rather lean. Gating at least the major stations would make a massive difference to fare evasion rates.
I accept that individually you may not intending to avoid a fare and understand your reasoning, but that is not the case in many instances.
Unfortunately, gating all major stations in not the answer either. All an automatic gate ever does in reality is that it protects the minimum fare as far as the next station stop only.