Like I pointed out, the power down period changed from 104 weeks to 13 weeks at the end of 2016. It was meant to be a seismic shift, bring in mass dumps. Never happened. Half a year later, price was 20x higher than before that change was made. The point is - it locks in people from dumping when there's market panic, to be sure. But it also reduces liquidity dramatically, and the lock-in period has a negative psychological impact on crypto whales.
Also, pretty much every other crypto asset out there does not come with a lock-in period. Most are completely liquid. Yet, they are valued far higher than Steem, despite having a fraction of actual usage. I mean, many of them don't even have working products!
There could be a short term dump, yes, but I'm confident long term this will make STEEM a far more investor friendly token, and lead to orders of magnitude higher volume.
Your first point on the change of lock-in period of 104 weeks to 13 weeks which you claimed was 20x higher could be due to the rise in interest of crypto currencies. In fact, during 2017, the entire crypto market was on the rise, steem included.
I agree that having SP as a form of lock-in reduces liquidity. I totally agree on that. But then again, you could always choose not to power up and just keep liquidity steem. I think it's a fair for those who are investing in the steemit platform for the long term vs those who are just opportunistic.
I wonder if this is a mechanism created by dan as an experiment for EOS.