One point to consider... I think it's very agreeable, that we need to grow this hobby (and your track business as well). My opinion is, that carpet helps new racer growth more than asphalt. For example, for road course, touring is comfortable on either carpet or asphalt, but the 2nd biggest class is 1/12th, and it takes more driving skills to run 1/12th on asphalt. Therefore it can frustrating for new racers. 1/12th is gaining popularity lately for many reasons, but I think one of the biggest reasons is the 1/2 price compared to touring. Half the price to purchase, half the parts, less weight (tires last longer), etc. If you go asphalt, you'll be encouraging new racers to go with the more expensive touring class, because they are easier to drive.
Another thing to think about, in the US, the 3 biggest races (Snowbirds, Cleveland, Las Vegas) are all on carpet. I know that many racers enjoy practicing for the big races at their local tracks if it's carpeted.
For me, I learned on asphalt, and wouldn't mind racing on it. However, I think the growth of the hobby is important right now, or else we'd have limited to no selection of racers to race with.