Better served to students and those unfamiliar with the field, but noisy to those familiar. Considering that much of mathematical work is done using pen/paper, it would be a total pain to write out huge variable names every time.

Consider a simple programming example, in C blocks are delimited by `{}`, why not use `block_begin` and `block_end`? Because it's noisy, and it doesn't take much to internalize the meaning of braces.