Yes, it's a loss of control but the way it was presented here was like watching Bruce Banner Hulk out; we can't
wait until he catches up with the bad guys and gives them what for.
I feel that the first movie handled his outburst far more effectively, displaying genuine consequence, remorse and embarrassment. Having done so again in this movie (as part of its climax no less), a Spock-out has now become a thing that we're to look forward to
and expect which I think is mistake.