I think this is just it: text has a higher information density than (say) visual programming tools. At some point you quickly reach an amount of threshold of complexity where you either need to:

1. Hide parts of the program (e.g. hidden cells on a spreadsheet; attributes of nodes in a visual programming environment)

2. Switch to text for the higher information density.

I think the burden of #1 quickly surpasses the burden of learning to work with #2.