Joe, I do not appreciate being called a liar... and I am sure the fellow you responded to originally didn't either.
I can easily set up an antique Apple Mac IIsi to work with a "STANDARD" VGA monitor with one of those adaptors:
Adapters were made for both nine and fifteen pin monitors. Heck, I had a bag full of them in my garage... several dozen assorted types I bought at an auction at a local college that I eventually sold to a reseller... Using this simple adaptor, the IIsi would, however, be limited to the standard VGA resolution of 640 x 480. With the one or another adaptor, you could hook the Mac up to any 15 pin VGA monitor. In fact, with a more sophisticated adaptor that allowed you to select the pin for the sync signal, the IIsi could support a VGA, SVGA (800 x 600), XGA (1024 x 768) and the Multisync monitors made by many manufacturers which allowed you to change rez on the fly.
Just because YOU couldn't do it says a lot more about your lack of knowledge of old Macs... and your attitude and rudeness toward fellow freepers says a lot about you.
But, Joe, what in hell does a Macintosh introduced 15 years ago and discontinued 12 years ago, have to do with a modern Mac introduced last week? Every Mac released in the past five years can use a standard PC monitor of any stripe either directly or with an included adaptor.
Now YOU can continue to live in the past... it's okay. Really... just don't spread incorrect information and call those who DID these things liars!