Why not

    puts {Hello!}
    # or even
    {puts} {Hello!}

? But I do not see an advantage either way. I think you attribute to quoting issues that are caused by type-punning. The quoting rules of Tcl are simple. I mostly encountered problems when people do things like

    # x is not actually a list, but may appear that way if a and b are nice
    set x "$a $b"
    # Proper way:
    set x [list $a $b]

But I fail to see how quoting could address or alleviate this.