Entirely difference reasons for equally spaced letters. Typewriters had no way of adjusting kerning pairs. The space between ho and lo are different in proport

Entirely difference reasons for equally spaced letters. Typewriters had no way of adjusting kerning pairs. The space between ho and lo are different in proportional fonts. These are called kerning pairs. So, it was mechanically easier to make letters of same width. Code is monospaced for many reasons others have replied here.