While I agree, it would be awesome to have this featured in the computer analysis of chess.com, there's an easy + free way to do this.
a) Download SCID (open-source chess database s/w)
b) Download Houdini (or your favorite free engine)
c) Plug the engine into SCID
d) Download your game and run an engine evaluation (setting a suitable think-time per move (defaults to 4-5 seconds)
e) Turn on the graph.
I prefer this DIY approach as I get to tweak and select my engine (and its parameters) rather than defer to chess.com's.
I just analysed a game where I made a few blunders and my evaluation score dived, then came back up again after a few moves.
It would be interesting to see a chart of the evaluation score over time.
I'm considering doing this myself as a browser extension if the owner isn't keen!