Giving Authors ability to delete replies they don't like (like on Facebook and Youtube) is highly contentious and will become a censorship tool to stifle debate and for lies and propaganda to be perpetrated on the public without appropriate scrutiny.
If steemit.com was the only interface to the blockchain I would agree however, this is not the case. Posts, comments and replies cannot be deleted from the blockchain. That is how the censorship resistance comes into play.
Have you seen how chainbb handles moderation? There the forum moderators can hide a comment or post but if you want to you can show all hidden posts with a click of a button.
The chainBB moderation is something I can live with, and similar to my compromise proposal.
If Authors were given the option to collapse/hide replies but not completely delete them from the site I would be ok with that, as long as the reader could undo the moderation with a click.
Instead Sneak is pushing for moderated comments to completely disappear from the site.
Dan and Ned promoted the Steemit social media site as censorship resistant, and that nothing would be deleted from the site unless illegal under US law.
This position has been maintained till now but it is about to change because 1 developer insists on changing this and we shouldn't complain cos "Steemit is not the only site". That's not logical.
Keep in mind that Steemit holds the vast majority of the Steem tokens. They are the only site in the Steem ecosystem with the financial capital to deliver a social media that can compete with facebook and google. The other sites have to raise funds by taking a cut on user's posts which will always put them in a marginal role.
The only real alternative interface to Steemit may become the Vessel App, and when that expands to include all social media functionality then yes the fate of the Steemit website becomes irrelevant....but at the current time the Steemit website is key in showcasing the power of the Steem blockchain. With censorship resistance being one of the key selling points.