"if they try to transform this site in a speculation, they will just sit with a ton of Steem in their hands... but Steem will be worth nothing!"
Well they don't have to sit on it, they can sell the steem dollars before the whole thing crashes.
Anyway, I agree it's not a ponzi, my own post on this: https://steemit.com/steemit-ideas/@sictransitgloria/steem-is-not-a-ponzi-scheme-but-it-relies-strongly-on-co-option-and-we-can-hope-it-will-get-better-in-the-future

It's funny that you posted twice the same post just changing the picture. the first got you a few cents the second a 1000$.