To answer the original question, yes i think thrusters should count as a critical component.
Without them you can't accelerate to engage your FSD and are stuck. It makes perfect sense to me.
Is it good or bad game design though ?
It's absolutely brilliant game design in my opinion.
Apart from the tactical possibilities sub-system targeting offers, it introduces a rarely (if ever) seen form of gaming death.
Not blown up into a million particles or butchered into a pulpy mass (and the instant realization that comes with that). No, the game gives you time to realize that you lost, and on top of that
forces YOU to put an end to yourself.....in a "well, how badazz are you NOW, Commander ?" way.
That is a truly cynical and brave design choice as far as i'm concerned.