There needs to be a balance.
Allowing advertisements isnt a bad idea. It would increase popularity for the platform, bring a greater return, and would benefit the community over all.
However, steemit becoming dominated by ads (say, like facebook) would destroy everything its trying to be.
The problem is its a slippery slope and a difficult balance to strike. We should allow ads, but they need to be strongly regulated and specific.
Steemit is attempting to change the way social works and is potentially revolutionary in its approach. The way it chooses to approach ads should be no different.