I didn't say that it doesn't work. It has been a major part of the anti-abortion and pro-gun movements as well and it has been very effective there.
However your quality of life in society is much more important than any single issue. Knowingly voting for a candidate who is not competent just because you agree with them on a single issue will not solve any of the larger issues in society.
Consider you have to 2 groups, A and B, and a set of issues. Each issue has different importance to me and each group has a generally opposing stance on each issue.
One group may have a stance on a subset of issues I generally prefer but more importantly the other group could have a stance on issues that terrify me. Their stance would lead to negative outcomes much worse than negative outcomes from the other group. It could even be that I disagree with many of the stances of the group I vote for but I’m not terrified of the outcomes associated with those stances.
So it is therefore more important to win to stop the opposition group from producing undesirable outcomes.
You're misunderstanding issues versus the mechanism of issue management. You're saying ability to manage issues is less important than any issue being managed, which makes no sense.
Unless, of course, you don't believe in democracy and an election process.
I believe in winning so the issues I care about most are either acted on or prevented from being acted on. Without winning it’s pointless. You need to win to take power so winning is the most important thing before anything else. Everything else has winning as a prerequisite.
However your quality of life in society is much more important than any single issue. Knowingly voting for a candidate who is not competent just because you agree with them on a single issue will not solve any of the larger issues in society.