Reason #3 is not in itself a reason to forego spaces, just a reason why users would not insist on them. And no newsreader or actor today would prefer his cue ca

Reason #3 is not in itself a reason to forego spaces, just a reason why users would not insist on them. And no newsreader or actor today would prefer his cue cards or autocue without spaces. I suspect a major reason not listed is inertia: people were used to reading without spaces between words, and never considered the alternative. With some help from reason #2, the increased cost.