This is not the first nor the last (moronic ?!?

) discussion on "shape first" vs "strength first" phylosophy.
Of course both approaches are the end-members of the requirements of bidding: 1) the search for a fit; 2) limiting the hand.
Both requirements are needed of course, but in some instances one is a higher priority.
For instances, in a contested auction, shape first tends to payoff more often; the same applies in a POTENTIALLY contested auction.
However, when opener has a shot to a rebid with silent opponents, then the urgency of delivering "colors-first" is much less (E.G. IF OPPS WERE TO BID, THAY'D ALREADY HAVE DONE SO, PROBABLY AT LEVEL 1)
In my opinion, in a forcing auction with silent opps, it is much more important to keep the bidding low with "normal" hands.
We can sacrifice an idle bid such as the 2M rebid by 1M opener, in order to define better (in terms of overall hand strength and/or suit quality of more shapely hands) the others that bypass it (I'd go as far to say that THE FIRST STEP of opener's rebid should be an artificial idle bid - but this would start yet another moronic thread !

)
The price to pay for it seems to be (both in terms of frequency and magnitude of the losses) quite low, on percentage.
A side note about the use of 4th suit forcing in a 2/1 GF framework: I do think this is really an unsound treatment to rely on 4sf as a further asking bid: it does eat tons of bidding space (when setting a GF is not really needed anymore) , so much that I think it is really unplayable. :-)
Just my 2 cents of moronic wisdom :-)
"Bridge is like dance: technique's important but what really matters is not to step on partner's feet !"