Making choices is a part of web development and choosing not to include an audience based on the technology they use is a choice. It's perfectly valid to make that choice--even if it excludes people--but it's a choice (that should be) dependent on the audience you are trying to serve.
For example, I support a few websites aimed at farmers. The sites are simple and degrade gracefully, because farmers tend to use older technology; small, because farmers don't typically have access to broadband internet; and mobile-friendly, because data access via cell phone is often more reliable for them than a consumer internet connection. These sites are not impressive, but they suit their purpose and their audience. So, obviously, the technology choice can go backwards as well.
Side-note: one of my favorite games is "breaking" websites by opening them in IE8 and reloading them with "Compatibility Mode" turned on.
For example, I support a few websites aimed at farmers. The sites are simple and degrade gracefully, because farmers tend to use older technology; small, because farmers don't typically have access to broadband internet; and mobile-friendly, because data access via cell phone is often more reliable for them than a consumer internet connection. These sites are not impressive, but they suit their purpose and their audience. So, obviously, the technology choice can go backwards as well.
Side-note: one of my favorite games is "breaking" websites by opening them in IE8 and reloading them with "Compatibility Mode" turned on.