Not at all. In the new "drop in" lowering kit from Progressive there are two springs per fork; one for suspension and the other to lower the bike. The difference is that you don't have to disassemble the fork and place the second spring under the rebound damper to shorten the tube's effective length. It's a trick installation idea to put a softer spring under the preload tube to lower the bike without making the suspension too soft or mushy. Check it out:
http://www.progressivesuspension.com/dropin/index.html
