> Кто-то тут раньше говорил про хвалёную обратную совместимость
> со старыми приложениями в Windows. Ага, по факту она только
> в маркетинговых материалах, а на самом деле

...и уже давно:

---
The Raymond Chen Camp believes in making things easy for developers by making it easy to write once and run anywhere (well, on any Windows box). The MSDN Magazine Camp believes in making things easy for developers by giving them really powerful chunks of code which they can leverage, if they are willing to pay the price of incredibly complicated deployment and installation headaches, not to mention the huge learning curve. The Raymond Chen camp is all about consolidation. Please, don’t make things any worse, let’s just keep making what we already have still work. The MSDN Magazine Camp needs to keep churning out new gigantic pieces of technology that nobody can keep up with.
[...]
Inside Microsoft, the MSDN Magazine Camp has won the battle.
The first big win was making Visual Basic.NET not backwards-compatible with VB 6.0. This was literally the first time in living memory that when you bought an upgrade to a Microsoft product, your old data (i.e. the code you had written in VB6) could not be imported perfectly and silently. It was the first time a Microsoft upgrade did not respect the work that users did using the previous version of a product.
And the sky didn’t seem to fall, not inside Microsoft.
--- http://russian.joelonsoftware.com/articles/howmicrosoftlostt...

Это человек, который достаточно поработал в некрософте ещё тогда, когда там озадачивались этсамой обратной совместимостью.