Software can (maybe) be perfect, or it can be relevant to a large user base. It cannot be both.
With an enormous budget and a strictly controlled scope (spacecraft) it may be possible to achieve defect-free software.
In most cases it is not. There are always finite resources, and almost always more ideas than it takes time to implement.
If you are trying to make money, is it worth chasing down issues that affect a miniscule fraction of users that take eng time which could be spent on architectural improvements, features, or bugs affecting more people?
If you are an open source or passion project, is it worth your contributors' limited hours, and will trying to insist people chase down everything drive your contributors away?
The reality in any sufficiently large project is that the bug database will only grow over time. If you leave open every old request and report at P3, users will grow just as disillusioned as if you were honest and closed them as "won't fix". Having thousands of open issues that will never be worked on pollutes the database and makes it harder to keep track of the issues which DO matter.