Your are right, powering up or holding as liquid are the options investors have. Powering up might not be attractive for some because of 3 month lock of assets. Holding as liquid may not be attractive for some because there are many other options.

Third option I suggeated, I believe would attract many investors who already hold crypto assets.

Steemit Inc has enough SP to cover all new or old users. I doubt many whales would take advantage of it, as they would lose an ability to delegate themselves.

Once investors are in and get to know the Steem blockchain I believe they would choose to power up themselves.