Biggest reason I've ever seen for this ordering is Data Reuse:
Putting the 'Boiler Plate Stuff' first, followed by 'the Variables', offers a slightly more consistent workflow.
Find an issue in Screen X for when you press button Y, look up past ticket from when button Y did something weird a few builds back, clone it, clear the Observed/Actual Results, and replace with the new content before filing the ticket/report.
Anyone working with Button Y's bugs becomes familiar with the ticket layout, and visual spacing on the ticket remains consistent.
- At least until a change in expected behaviour of Button Y is introduced, in which case the break in consistency adds a subtle highlight to the change.
It is horribly minor, and in the end the ordering standards for a given project aren't actually all that important:
Are all perfectly valid orderings on Tickets/Reports that I've used on projects, and they all work just fine. The only thing you want to avoid is constantly changing how you order things, or having different people order things different.
If everyone else is already using the first order from the above list, and you have a burning desire to use something else... Then just use the existing order anyway. At least until you can convince the team that your way is better. [And that is often not a fight worth having.]