Heh, I don't think we're really even disagreeing THAT much, but just to reply...
In terms of Ragtime, yeah I like the idea of underscoring. I did just see the production at Paper Mill and have been listening to the cast recording ever since, so I could be biased in knowing the song so well and adoring it on the CD.
Now in terms of WSS...I think the difference is in the two characters personalities' and what they are discovering. Of course it would be inappropriate for Maria to sing a ballad like that, as this is the moment where she becomes strong enough to be the Juliet that lives. Her dead-on screaming w/o singing serves perfectly to oppose her at the very beginning of Act 2, singing the happy little lala of "I Feel Pretty." It is soo perfect...god...did I mention this is prob my fav and best show ever?
I wouldn't say that definitely applies to Coalhouse here. The whole show he's been struggling w/ how to approach the injustices he's faced. He started out very calm, and then turned extremely violent. I think the song serves to show he's returned more to his calm demeanor and has totally overcome the change in the personality, and this song reveals that in the character, again I find it appropriate.
But I do see your points. Maybe we shall agree to slightly disagree?
"If there was a Mount Rushmore for Broadway scores, "West Side Story" would be front and center. It snaps, it crackles it pops! It surges with a roar, its energy and sheer life undiminished by the years" - NYPost reviewer Elisabeth Vincentelli