Having done a ton of COM programming in Delphi, the problem wasn't that it didn't work that well — the language integration was fantastic, and things like Query

Having done a ton of COM programming in Delphi, the problem wasn't that it didn't work that well — the language integration was fantastic, and things like QueryInterface and AddRef/Release were done for you — but the support wasn't quite good enough. The typelib editor, for example, was atrocious in Delphi 4 (maybe it got better in later versions), and if you wanted to use a COM-based library (MAPI, TAPI, OLE DB, etc.) you couldn't do it without the headers. Since so much of COM came from Microsoft, it felt like fighting a losing battle against the official way of doing COM programming (Visual C++, at the time). Ironically COM programming seemed much worse in VC++, given the lack of language integration.