Hi Malcolm; allow me to retort :)
Every company needs revenue - Indeed they do and this one will generate that revenue via a cryptocurrency that gains value as more people use the blockchain.
I'm not sure I understand the point, so won't comment
Advertisers don't care about content - Erm, tell that to Tiger Woods, Lance Armstrong, FIFA and just about any other large organisation that has had scandal. Under your model for instance; you might decide to do a whole series of articles on the evils of sugary drinks. The posts get popular, really popular, people start to notice and share. However Coca-Cola are a major sponsor of the platform, they get annoyed at how popular your posts are getting, so they have a quiet word in the ear of the platform. The platform, not wanting to lose a major sponsor, surreptitiously start removing your posts from the pages of certain demographics, to negate the chance of Coca-Cola advertising to the same people you are telling not to drink their crap.
That's a best case scenario, the worst case is that they start to censure you without your knowledge, so your posts, get edited to sound a little less cutting than you first intended. An algorithm stops you ever seeing these edits.
Sounds far fetched? Google the following term: Facebook engineers admit to censoring Oh and do that in an incognito Google window and look at the difference in results. Now those stories are talking about Mark Zuckerberg and Facebook in general censoring for political reasons, however faced with losing contracts, news givers will listen to advertisers. This has rung true since the first company paid the first newspaper money to advertise.
OK, I'm not going to labour this point, because I'm not an expert, but as I understand it the blockchain is generating wealth by creating Steem Dollars which (as it stands) have a monetary value. These Steem Dollars are then distributed ad infinitum.
This argument is a good one and I have recently written an article on here addressing those points, if you're interested you can read it here if you're interested.
What I would say though, is that at one time, I was a general customer and then I heard that something I buy regularly was offering 33% off paying by Bitcoin. It was painful to go through the process at first, but once I did it one or two times, it was fine and I became a cryptowarrior :).
Ultimately, if you want to use this system as a way to a quick buck, it will disappoint for the reasons you mention and more, however if you want to get in at the bottom on an innovative platform that may well change the way we blog, then Steemit is for you.
Also like you mentioned briefly, other platforms can and will use the Steem blockchain, as once Ned and Dan reduce their stake past a certain point, the blockchain becomes available to whomever (I think). So hey, it's an experiment, a social one and one that I personally think can work. Maybe I'm wrong, only time will tell.