Because if you want the 09xx effect to work you must enter the note as well. I’m talking about when you already have the note entered somewhere above that point, of course.
Why not just make it work like the volume value?
Same for the other effects.
I haven’t thought about this thoroughly (about possible complications…), but I think it’d make working a bit quicker.
Not a “high priority” request, tho.
Currently the 9xx effect triggers all instruments in each very subtrack of that track that are instantiated on that very line. If you would make it to trigger sample offsets all the time you might cut yourself in the fingers when it would trigger instruments you’ld rather wouldn’t trigger.
No offense but i think realisation of such idea would probably be more a pain in the ass for a lot of users than a benefit.
And imagine this stuff implemented: as a bonus, all older songs have to be altered and all subtracks containing instruments that are not desired to be included in the 9xx behaviour, have to be copied to a seperate track.
This is what the user has to manually do himself.
I think they will all be very thankfull to you for that 
Yeah, you’re right, I can see the complications…
But no big deal, really. It was just a minor suggestion, anyway.
The solution might be if the subtracks (note-columns) had each its own effect-column, no?
But there could be problems even like this, especially with the backwards-compatibility.