With-out stirring up too big a debate,(I know a few will bite)If the engineer is removed from pre-flights (first flight of the day at least)How closely do you expect pilots to do preflights (most tend to look at the maintenance log carefully and glance momentarily at all other areas).I can't say that I've ever seen a pilot checking for life jackets being fitted(yes they do get removed,and not only for maintenance)nor climbing into wheel-wells checking off- wing slide bottle pressures (B767).The list goes on and on and wether it is relevant or not the words "Affordable safety"spring to mind.
If economics isn't the issue What is ??