Rationality Quotes June 2016

Another month, another rationality quotes thread. The rules are:

Provide sufficient information (URL, title, date, page number, etc.) to enable a reader to find the place where you read the quote, or its original source if available. Do not quote with only a name.
Post all quotes separately, so that they can be upvoted or downvoted separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
Do not quote yourself.
Do not quote from Less Wrong itself, HPMoR, Eliezer Yudkowsky, or Robin Hanson. If you'd like to revive an old quote from one of those sources, please do so here.
No more than 5 quotes per person per monthly thread, please.

Another month, another rationality quotes thread. The rules are:

Provide sufficient information (URL, title, date, page number, etc.) to enable a reader to find the place where you read the quote, or its original source if available. Do not quote with only a name.
Post all quotes separately, so that they can be upvoted or downvoted separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
Do not quote yourself.
Do not quote from Less Wrong itself, HPMoR, Eliezer Yudkowsky, or Robin Hanson. If you'd like to revive an old quote from one of those sources, please do so here.
No more than 5 quotes per person per monthly thread, please.

It's a moral imperative that we must create this.

John Carmack, speaking of the Holodeck/Virtual World concept.

Quoted by David Kushner in Masters of Doom, see also here.

Did he give an explanation of why he thinks that would be a "moral imperative?"