Earlier quoted context omitted.
I'm with you there -- I find Cygwin starts slow and unstable, and then seems to rot at an astonishing speed, to the point where it's usually unusable after I've had it installed for a couple of months.
Cygwin doesn't rot. It doesn't automatically update, and nor does it self-configure, so there's nothing to cause the rot. I've never had problems like you describe. The biggest problem - and what I suspect is happening to you - is when you have third-party programs and utilities that interfere with Cygwin, most often by putting an older or newer version of cygwin1.dll on the $PATH (i.e. you may be using Cygwin as par…
In any event, I much prefer Cygwin to the alternatives.