@Coagie
There's a practicality consideration though - namely that there are only so many simulators in the world, but there are a hell of a lot more single-engined trainers.
Also, I think focusing on hand-flying finesse is only one facet of the issue. Another biggie for me is the situation whereby recurrent training at ATPL level can assume familiarity with the basics, when those basics can atrophy without revision. As an example, I'm thinking in terms of the airline industry focusing so hard on stall prevention training that those techniques supplant stall recovery training, which many pilots hadn't practiced since their PPL days.