I think to appreciate the TV Typewriter you have to appreciate how freaking expensive printers and typewriters were relative to the cost of the computer[1]. Don't TVT was 16 x 32 because that was exactly 1024 characters which fit in one static RAM chip. The Apple ][ could, and did display 40 columns (also 16 rows) on an unmodified TV. That kind of output was SO MUCH more useful than looking at the blinking lights on the front panel. It was also cheaper than what a 24 line by 80 character terminal would cost you.

[1] http://www.bitsavers.org/pdf/pacificOfficeSystems/Pacific_Of...