"Do we only want the super engaged and hardcore people on Steemit? Or do we want more casual people as well?"
It is a balance act though, because increasing the bandwidth too much would make spamming worse and I don't think anybody wants that.
100% agree we should get some mathematicians to do some statistics on this, trying to find a balance is hard, and yes, i think in the future we will need a small bump in bandwidth, i'm thinking it won't take more than 1 year for that small increase, probably in the summer... Let's wait and see