Earlier quoted context omitted.
That's not a great example given OpenSSL versions are famously backwards-incompatible. Older versions get ABI-compatible security patches because people put in the time to backport all of them to every version still supported, in many cases by distro package maintainers. It's exactly the situation libraries should generally avoid, because there are maintainance costs for older versions of the library as well as migra…
Well given that i upgrade but not downgrade… what's your point?
The point is that someone is paying the cost of maintaining the library's ABI surface area even if it's not you. In a thread specifically for developers considering how to offer an interface to their software, I think it's only fair to recognize the costs of those different approaches. In that regard, OpenSSL is an extremely bad example, or an extremely good example of what not to do.