Well, that's what I thought as well, but I got caught out today (not heaping sh*t here...just trying to get an understanding!) by one who was assigned 190kts base, turned onto final about 12 miles out and had slowed himself to 160kts without being asked. Almost got a little tight for the A319 following behind at what I thought was a slower speed. (We won't go into the old "Slowing up without an instruction argument"..once again, not here to heap it!)
I remember the SI going out for the "standard" speeds, yet have seen pilots happily accept 180/160 kts as before. I always try and allow as fast as possible, but sometimes for what ever reason (too many a/c off the stacks when landing on 09...very easliy done) different speeds may need to be applied.
Just looking for drivers points of view as to why sometimes yes and othertimes no.......