17 days without an acl and without a brace? Awesome...
It's interesting to think that I had predicament as you a couple of years ago. My life was also skiing, and the prospect of not being able to do so for a whole season was pretty tough to think about. I was also counting on skiing for my job, as well as performing at a relatively high activity level for many of my university courses. My doctor, who operates on the knees of the Canadian National Alpine Team (Dr Mark Heard), told me the opposite of what yours said. I have also personally done a lot of research into this area (I'm 2 weeks away from graduating with a kinesiology athletic injury degree). The excess movement WILL give you osteoarthritis. The only question is, how soon will it happen?
I made the decision to take a season off and get completely rehabilitated before going back to skiing. Yes, it was extremely difficult. I was depressed and angry and it all around changed my life for close to a year. But I'm so glad I did it. Now, I can look forward to continuing my active lifestyle and skiing for the rest of my life (not counting other injuries that I will incur, but thats another story). I put in the time to fully regain my strength and range of motion, and now skiing without a brace feels just as great as before I got hurt! Also, the year off let me put more time into school, which will hopefully allow me to pursue a master's of physio in the near future.
I don't want you to think that I am criticizing you in any way. I fully understand how you are feeling and the choice you have ahead of you. But I recommend asking maybe your physio or a different doctor for advice. This decision is huge. Remember, you only have one body, and it has to last you the rest of your life. You're not indestructable, and not everything can be fixed. Yes, improvements in treatments for different joint problems have been made, and will continue to do so. But don't bank on that to keep you skiing through the next 30 years.
Good luck.