No, I don't think your analysis is correct. The interferons are older, more established drugs. They've been around longer, there are long-range results as to their efficacy, and doctors are generally more comfortable prescribing things that are older and more established, and drugs that they've had the most experience with, with their patients. Your doctor may really like Avonex, had good results with it with other patients, and so started you on it. While they *sometimes* can affect a patient's liver, they certainly don't always do that. As I noted, I've been on Betaseron for over 12 years now, and have experienced no liver problems.
Copaxone is newer. While the results have been excellent so far...and there was just some results published the other day from Britain, talking about a combination of Copaxone and another drug and how successful that was --
while the results have been excellent so far, it hasn't been around as long as the interferons, so doctors often will start with those first, and if the patient has difficulty, then switch to the copaxone. It has been around for, I think, 8 years now or maybe longer...and well established...just not as long as the interferons (for 15 or so years.)