Why?:
"[I]t has been increasingly difficult to remain effectively focused on the instructional agenda for our students."
What caught my attention:
"Johnson is the fourth highest paid superintendent in Texas, with a base salary of $328,950, according to data from the Texas Education Agency. Her contract also allows her to receive an annual car allowance of $7,200 and an annual performance bonus to buy retirement credits."
If not for the resignation taking effect in September instead of immediately, I'd think something was going on.