I don’t think he killed it “because it wasn’t NeXT software”.
I think he killed it because the market didn’t support it (MS Office showed that an ‘everything but the kitchen sink” solution could conquer the market, leaving only breadcrumbs for smaller parties) and to focus the company.
But MS Office is sort of the implementation of what the article describes, with it being thoroughly COM based. You can embed pieces of Office in your software, or pieces of your software in Office (including saving its state in the MS Office's documents).
Technically, sort of, yes, but sociologically: no. Office doesn’t (seem to) use it itself. If you can insert an Excel table into a Word document, why does Word have table functionality on its own? Why does Excel have its own text box for styled text? Can I embed a Word table inside another document without getting the entire Word editor? An Excel table that’s just a table and not a sheet to which one can add charts, etc?
Also (and possibly alongside “we sell Word/Excel separately, too, and want it to be everything but the kitchen sink, to prevent others from providing missing parts”) the answer to that may be “because the UI of OLE-embedded parts isn’t as smooth as it could be”. Outside-in activation (which, reading http://preserve.mactech.com/articles/mactech/Vol.10/10.08/Op... doesn’t seem to be required with OLE, but I haven’t seen otherwise) means you have to click multiple times to start editing (clock to activate an OLE control, then click to start editing it)
OpenDoc promised much more, but of course, the market didn’t want to deliver it at the time, and we also don’t know whether its promises really can be fulfilled (Cyberdog was cute, though)
I think he killed it because the market didn’t support it (MS Office showed that an ‘everything but the kitchen sink” solution could conquer the market, leaving only breadcrumbs for smaller parties) and to focus the company.