Your counter solution is fine, but that explanation would need to be both concise and correct enough that people would actually read it, which is hard. Hiding the button in "advanced features" is still better, IMO.
You write
Being paid directly in a set amount of Steem would lead to periods of glut when Steem is up and periods of famine when Steem is down. Periods of glut would be OK for Steemit, people would still contribute. However, the periods of famine would be bad because contributors would not be paid very much and contribution would drop off.
That's precisely how it works, except the Steem is paid as SBD. Everything having to do with the rewards pool is denominated in Steem; the rewards are only converted to SBD at the moment of payout. Back when Steem was 10 cents, people were being paid a tenth of what they are now.
Yes, 'concise and correct' is very important.
What I was getting at in the quoted text is 'directly in Steem', not in SBD that is effectively an IOU for Steem. The overall semantics of this passage is meant to be an argument for why SBD exists in the first place. Does that clear that up for you? Basically, it is an explanation of why being paid in Steem directly is a problem and the solution to that problem is SBD.