In order for bulk download of users to work when there is a text area user profile field a change is needed to the textarea.

First, create a User Profile Field of type "textarea".
Then, go to:
Site Admin > Users > Accounts > Bulk User Actions

Select a collection of users, then go to "With selection of users..." > Download
And pick the Excel type

The current core functionality will download as:
profile_field_comments
Array
Array
Array
Array
Array
Array

Instead of the content of the text area. If you make the following change to
/user/profile/field/textarea/field.class.php
It resolves the issue (commented line is the current code, and the line below it is the proposed replacement)

function edit_load_user_data($user) {
if ($this->data !== NULL) {
$this->data = clean_text($this->data, $this->dataformat);
//$user->{$this->inputname} = array('text'=>$this->data, 'format'=>$this->dataformat);
$user->{$this->inputname} = $this->data;
}
}