So if those who don't really want to be instructors don't, who then, will instruct for say $30 000 a year with a maximum earning potentially of say $49 000 a year?
The fact is the desire to get to a jet underwrites the whole industry. If people want career instructors then they better start paying higher salaries and offer better lifestyles because noone is that stupid. Look at school teachers, start on $40000 a year, 12 weeks holidays, every weekend off etc etc. Compare that to flying instruction. You're cracking jokes if you think that people want a career like that.
Do not do a bare commercial, get an instrument rating at least. The last thing you want is to be bypassed on a twin because you didn't have a instrument rating.