From a usability and design standpoint, required field asterisk generation should be removed, and not be something that turns on/off by default.
If a user wants to denote a field as required with an asterisk, they can add it to the field label. Sometimes, every form field is required, and its easier to simply insert a html field with "all fields required", than to flood the form with asterisks.
Modification: form_display.php - Line 1755
$required_div = IS_ADMIN ? sprintf("<span class='gfield_required'>%s</span>", $field["isRequired"] ? "*" : "") : "";
note: || rgar($field, "isRequired") has been removed.