I strongly disagree as well, as I expressed in the Github issue that was made yesterday titled reduce post payout options to only two: 1) decline payout 2) SP only payout (default).

Many users take pride in their SP and wouldn't want to have to power it down. This also erodes the original concept and selling point of stakeholder participants, where people are more likely to treat half of their posting rewards as their reputation, their sweat equity into Steem by way of Steemit.

People will be forced on a powering down-track, potentially selling the other half of their posting rewards at the same time. Val mentioned that restraining steemit.com users from taking posts in liquid tokens would reduce downward pressure on the STEEM market but I think it would do the opposite. This has too much potential to make Steem Power become even less distributed.

I think @smooth's comment here and his comment on github are on the money:

Also, putting this in the UI means that people using non-standard tools/bots/auto-reposting services, etc. will have an extra option that ordinary web UI users don't. That seems like a recipe for further dissatisfaction and resentment. If this is a good idea it should probably go in the blockchain and apply to everyone.

I believe existing and potential Steemit users will not appreciate it at all.