No, I don't think it should be prescription-only. For several reasons already stated.
The key is definitely to provide more breastfeeding support. REAL support from people who know what they're talking about... so maybe more breastfeeding education for pediatricians/health professionals that work with infants? I don't think it should come to having to track down a lactation consultant to get support, it should be easily accessible just by picking up the phone or asking questions at a regular checkup. And every hospital should have a lactation consultant on site for new moms who are struggling - my hospital didn't have one and a couple of the nurses trying to help me were lost. They ended up suggesting that we supplement because we couldn't get her latch right a mere 12 hours after she was born... I was devastated and it was seriously disappointing. I felt like if I had proper help we could've avoided a lot pain as I ended up going home with her not latching correctly and the nurses basically saying "Oh well, just supplement."
For a lot of people I'm sure that would've ended in a complete switch to formula due to not establishing a good supply, or quitting because we never got the latch right and it was excruciatingly painful. Fortunately for me, I had this forum to look to and I got things back on track. But not everyone has that, and I'm sure lack of support or information is the reason a lot of people use formula. That can be fixed without putting restrictions on formula.