Why has xfinity killed streaming on old computers?

Why did xfinity intentionally kill browser-based streaming just because it's running on an old computer and operating system?  The whole point of browser-based SAAS is that the operating system doesn't matter.  I don't want to tie down my main PC with one monitor watching streaming, so I set up an old Windows 7 PC and use it only for streaming.  It's old, but until now it was handling the job just fine.  This decision wasn't technology based, it was simple malice.  Typical Comcast.