Leaving a mooring/anchorage under sail

[poiu]

I'm curious why this is done.

I'm not sure if all the facts are relevant: a common scene is a boat prepares to leave an anchorage or a mooring, very often it is a French cat with maybe 8-10 crew or maybe a monohull with 5 or 6 crew. 2 or 3 of the crew are supervising, they are often female, attractive and wearing very little. The procedure is to put both engines on, hoist the mainsail sheeted in, but flogging, maybe reefed if the wind is up. I've seen this done in up to 30kts. Then pull up the anchor/mooring line and drift rapidly back due to the high windage, sometimes just missing other boats and maybe the odd reef. Then they will motor off sometimes jibing or tacking a few times following a slalom course through the other boats until into open water.

So what is this all about then? Is this a genetic link to a past time before the evolution of auxiliary engines?

Wouldn't it be so much safer just to use the engines and to forget the sail? They have redundancy after all.