insert account variable for campaign email template

[pixprotom]

Can someone explain to me why it is possible to add an account variable when creating an email template but when sending out a campaign email I can not add a variable from accounts.
Would it be so difficult to include this module in the campaign templates since it is also available in non-campaign templates.
Seriously, why is it like this? I need to be able to explain this to customers why they can't do what they want to do.