response format - is it a bug?

Response xml has such structure:
<response>
<result>
<TaskDetails>
<TaskDetail>
                task 1 details....
</TaskDetail>
</TaskDetails>
<TaskDetails>
<TaskDetail>
                task 2 details....
</TaskDetail>
</TaskDetails>
</result>
</response>

I don't understand why couldn't it be in such way, the result would be the same, list of tasks:

<response>
<result>
<TaskDetails>
<TaskDetail>
                task 1 details....
</TaskDetail>
<TaskDetail>
                task 2 details....
</TaskDetail>
</TaskDetails>
</result>
</response>

In responses from Zoho, <TaskDetails> always contain one <TaskDetail>.
Why is it that way? Is it a bug or feature?

thanks,
Mariusz