What kills those products is not the bad code itself, it's the side-effects piling up: added dev expanses, lagging behind the competition in adding new features

What kills those products is not the bad code itself, it's the side-effects piling up: added dev expanses, lagging behind the competition in adding new features, performance problems as app grows, etc. Badly written code is simply more expensive to maintain and improve. I guess it's less of an issue if you have a very profitable product and/or enterprise clients who are much more tolerable to things like the simplest customization taking weeks to finish, integrations that are complicated and cost thousands and thousands of dollars, etc. For startups and smaller businesses that are tight on dev budgets it's much bigger of an issue.