the only reason Microsoft would not add binary transfer capability as an integral part of
early DOS is that the people that needed it were in a small minority. It made no business
sense to include features that they believed that most people really didn't need.
Later in DOS, they did include a basic file transfer capability over a cable. Probably
more out of pressure because people used products like LapLink and complained that they
had to buy something instead of having it built in. It was designed to transfer files (and
filenames) like a real software package like Telix would do when running zmodem protocol.
A programmer can write any software, but they still are employed by the company that hired
them and the product requirements. If Microsoft had put "everything" into early
DOS, then companies like Norton, Traveling Software, etc would have not even been
started.
I have long held the concept that Microsoft has always been a 90% solution and the
remaining 10% are the opportunities for outside companies.
best regards, Steve Thatcher