Ok, then take a look at how HTML does forward compatibility, for example. Extremely simple, elegant. Not that i defend lexable-parsable formats - I got the point that speed was important on stone-age computers. No. It's about architecture.

Here is what I think: nobody at Microsoft ever cared about making anything simpler than what they got after the first approximation, because complexity looks impressive and hence sells better. On the other hand, making things simpler requires more intellectual efforts and usually doesn't sell well, especially in the consumer product business.