This is changing though.
Version 3 of Reason added some pretty impressive mastering FX units to the rack.
Version 4 has added groove control functionality and massive improvements to the sequencer unit.
It's still far from offering the functionality of Logic or Cubase but it's come on in leaps and bounds.
After being a die-hard Cubase user for a long time I started messing around with Reason 3 on holiday earlier this year, and I was pretty blown away.