It really depends on the reasons they would bring them back: nostalgic value or emotional resonance, in cases like Mao's using her old SP this season as a tribute to her mother comes to mind.
But I think in some circumstances I have no problems bringing them back if the skaters feel they haven't used the program much. Yuko & Sasha used their beautiful Clair de Lune for two years, but part of that was because in the first year they missed their first GP assignment and thus could not qualify for the GPF, meaning that's two fewer tournaments they could have used it. The program was a work of art and is one of my faves. Another is Caro's Bolero, which she used only four times competitively (once was at Nationals) in 2012/13 and didn't really skate to perfection until her FS in Sochi. And there's the case of B/S, who received very polarizing reviews for their bizarre Four Seasons over the GP series and reverted to their (infinitely better) "Insanity" routine from the previous year.
That being said, it puzzled me that Chan didn't come up with something more innovative or new for either programs during the Olympic year. That was disappointing to me. And then Petrenko used the same program forever. When that is done more than once, I would simply think that the skater and / or choreographer either didn't have the funds to put something new together (doesn't it cost $10K for a new program?), or they had run out of ideas.
Sometimes, they may do it because they're guaranteed crowd-pleasers. Prime examples are Joubert's Matrix and Plushy's "Best of Plushenko" FS in Sochi. Admittedly I never get tired of either!
On the flip side, there are the programs which are underused or performed in a major tournament just once. Two prime examples are Yuna Kim's "Homage to Korea" FS and this past season's SP and FS, which she only really got to perform in Sochi. It would have been lovely to see them more than once.
Agree completely re: re-cycling so you can refine/perfect a program.