Not trolling you with multiple responses, but I'd just like to point out that this is only true if the STEEM ultimately finds its way onto the exchanges for BTC/USD via the token sellers. On the contrary, projects tend to find many reasons to power up the acquired STEEM or use it for long-term operations.
That said, Ethereum ICOs are much more likely to not have sell pressure on ETH due to the fact that those dapps are going to need ETH to cover gas costs for their applications. That is an ironic feature of free (or RC cheap) transactions on Steem, it does take away a potential use case for STEEM.
Some of this sell pressure is a good thing though. I would argue that the existence of 3Speak is causing sell pressure on Steem because they guys are charging content producers in STEEM and obviously they're paying bills with the STEEM, they have indicated that they need to do that.
Sell pressure is not always a bad thing and might be necessary. People complain about miners causing sell pressure, but what else can you do? The businesses validating the blockchain need to pay their bills! Sell pressure is a natural effect of businesses earning the blockchain's native currency and using it to cover operational costs.
Agree that selling pressure will always be there and it cannot be stopped. I think the important thing is whether there is sufficient buying pressure to counter the effect. It is a decentralized balancing act which no one can really predict. Even on hindsight, I cannot 100% confirm or deny what is the real reason for the dump. As I said, it is just theory :)
Great comment by the way, thanks!