That was only because Sony required it. They haven't done it since, which should say how much demand there is from fans, and desire there is from Harmonix.
Also, since Blitz...EXISTS, that should show they want it incorporated elsewhere.
One I haven't repeated in a while:
No-fail should give you grayed icons like that of someone who dropped in (grayed icons have no effect on the crowd meter), and the crowd meter would be topped.
I've recently been working on the Pro Bass goals and I can't seem to get the first trainer goal. I've passed all the trainers on easy but it's still showing I have Lasso to do.
I did the Pro Bass trainer for Lasso again on medium, still didn't help.
The icon itself can still move on the meter, it just doesn't have any effect on the colored part. Isn't that they already do for a drop-in player?
Personally, I'd revamp the crowd meter - have icons fall off for failure, flying back up to reattach to the meter when saved. If No-Fail is on, the icon will drop a little before flying back up automatically. This way, you can still see that you would have failed. No flashing red for No-Fail.
Wait, the sing-alongs weren't just for staying at the top?
Another thing: Only having a singer (nothing to trigger a BRE) should mean the "BRE hit" pyros (in arenas) always triggers. Found that out with a Performance Mode No-Fail run of "Kickstart My Heart".
The sing-a-longs seem much more emphatic in RB3; there've been times when I've been startled by sing-a-longs in songs that I'd played a gazillion times in RB2 ("Say It Ain't So" comes to mind).