You may have to explain why that's unexpected.
By design, (whether we agree with the design decisions or not), the resizing frame is "pinned" at the top. When it contains left-justified text it will "pin" at the top-left; center-justified pins it at top-center, and right-justified pins it at top-right...but it's always TOP...regardless of the vertical justification applied. I don't believe it can be changed.
Ah okay, that is exactly what I was asking. Can you think of any sort of way of 'cheating the system'?
Not exactly "cheating the system" but I've really sort of taken to the Text Frame Auto-Fit features in more recent versions of InDesign...to the extent that I've made Auto Fit Height Only (pinned at top) my default for new text frames. It can present complications if your project will contain many threaded text frames, but in certain workflows, it can be a real click-saver.
Can you think of any sort of way of 'cheating the system'?
You can script auto fitting so this AppleScript (OSX only) would work on a selected text frame:
tell application "Adobe InDesign CC 2014"
set auto sizing type of text frame preferences of selection to height only
fit selection given frame to content
display dialog "Please select a text frame"