Ilaksh, I seem to have touched a bit of a nerve here. I know, I used to respond the same way to similar advice. I wasn't assuming anything about anyone's condition - I was giving personal advice based on my experience. I say this as a person who grew up with extremely exercise-induced asthma - I used to run a slower mile than I walked (due to collapsing multiple times), went to the hospital multiple (6+) times a year (from ages 8-20), etc. Also, running in dry and not-salty humid climates is still a bad idea for me, or around certain kinds of trees. Running for 45 minutes was something I worked up to around the age of 25 - started with 5 or ten minute periods, interspersed with walking, until I was able to do another brief run, etc. When I stopped running for a few years, my issues came back, with multiple hospitalizations from 28-30, until I started up again around 30.
Part of the issue with exercise-induced asthma, for me personally, was also general nutrition and health - I found that as I earned more income, and switched to a diet higher in fats and vegetables and lower in carbohydrates, my condition significantly improved, providing a positive feedback loop with the exercise that eventually has brought me to being nearly symptom-free today (34). Your mileage may of course vary.
The main reason I focused so much on the running is because for most of my life I thought it would kill me, and always told myself that the reason that I didn't run is that it was bad for me. In the end it was exercising more and eating better (in a better environment) that saved me. Hopefully you'll find the trick for you - living with asthma is really unpleasant, to understate it.