Interesting topic.
Having been in the associate position before, and now as a practice owner (who has never seriously entertained the idea of an associate), I will take a stab at it.
After 4 years as a military dentist including a GPR, I had my skills and speed, and my first civilian job was at a corporate office. I was paid well, but the amount of work was very taxing. 4 chairs, 4 full columns, all day long. Quality suffered, as did my back and neck. After 18 months I took a job as an associate at a private practice.
My experience was good, and that is mainly because I got a job at an office that was long established, very busy, and the owner was at a point that he rarely worked (he had some health issues). I was full time at his office, and essentially got to run it as my own. At this point I was 5.5 years out of school, so it was a good fit, someone right out of school would not have been able to keep up, as I was producing about $100k per month, independent of hygiene production.
It was a good associateship, and lasted 3 years.
I was happy with my income (I was paid based on adjusted/true production) and the owner was happy that I was a quality, productive dentist that put money in his pocket and he had minimal headaches.
Essentially, it is about the quality and quantity of dental work being done by the associate for the practice, and the compensation for the associate.
In order for it to work, BOTH the associate and the owner need to benefit.
I know other dentists that were early in their careers who had LESS than satisfactory associateships.
It always boiled down to the money; both in terms of production, and in terms of payment/compensation.
The problem can come from either party: Either a greedy owner who tries to squeeze every dollar out of an overworked associate, OR, just as often, an inexperienced dentist, lacking in clinical speed and advanced skills, who EXPECTS to be making close to $200k a year within the first year or two out of school, without having developed the patient management and clinical skills to justify such a large salary.
Now that my peer group is mostly practice owners, I hear the owners side more often. I have even had friends show me example of borderline/poor quality endo and fixed pros work done by associates, who demand large salaries, and get offended when their work has to be redone by someone (usually the owner) with more skill.
Really there are no easy answers here.