No. It's because they rarely happen. It has nothing to do with doing the other GMs work. It has to do with the fact that at some point every GM is faced with tough negotiations and doesn't want to open a can of worms that could come back in the way of payback. It's an unwritten rule that you give the other GM heads up about your interest in the player before you send an offer sheet their way. There have only been 6 or 7 sheets in the last 10 years and 8 or 9 in the last 20 years. I laugh when so called sports experts talk about offer sheeting players in the offseason to try and stir up chatter among fans. They almost never happen. I'm not saying they don't or can't, I'm saying they almost never happen and it's funny when it's used as negotiation ploys through the media.
Weber, Sakic, Kesler, Bernier, Backes, Ohlund...I know there are are other big names, but those are the first ones that come to mind, and even then, two were superstars, and four involved the Canucks directly. 12 have been offered since 1997.
But Sakic's inclusion should be enough to show anyone thinking it's "just that simple" how rare and broad a selection of years are needed to accumulate anything close to a list of players.
Edit: And only 2 in 20 years were accepted and not matched: Chris Gratton and Dustin Penner. Gratton was traded back after 100 games, and pooping the bed, and Penner kinda, sorta, definitely dropped off tremendously.