Richards was out of shape this past year and easily could have had an injury that led to season-ending surgery and prevented the buyout. The Rangers dodged a bullet this year and were in a position to buy him out, but will they be so lucky next season? Richards is getting older, it's definitely a gamble.
Another thing to consider in the short-term... Are the Rangers fielding the best possible team with Richards in the lineup for 2013-14, or could that money have been better spent on depth, a top 6 LW, etc.? I'm hoping Richards bounces back but I'm assuming he will play similar to how he did last year. I don't even want to consider a 3rd scenario... that he will continue to decline and plays worse and is less productive than he was this past season. If so, it could end up being another wasted year for the Rangers, not ideal with Lundqvist about to hit free agency (if he doesn't re-sign before then).
There's just so much riding on this decision. I would have preferred the Rangers go the safe route in this scenario and just buy him out now instead of assuming that things will break right next year.