When working with the email templates, it is not obvious that there is a Source View unless you happen to be a programmer. If you are a Business users who is tasked with Updating the Email Templates, you might not notice and think you are editing that view since you can see the variables. This view also selectively removes formatting/code so it can make the template look incorrect and someone might try to fix with unknowingly.
This is the view that you are presented with when you open the “Access Request Reviewer” default email template:
You can see the part that is highlighted looks like it has " role entitlement access profile" improperly places there. This could cause someone to update the email template.
In reality, this section looks like the following when you use the Source View:
A better approach to this would be to do it similar to the way the Developer Forum works with 2 panels, where the left panel is the Source Code version and the right panel is the formatted version.
This would also work well for improvements with the Test Email idea to allow Real Data to be entered for testing. This real data could be handled in the same way that workflow testing works.