Interest in the incorruptibles appeals on several levels. One is that although sanctity is pretty obvious in the sanctified, it's still nice to have a crude objective and hierarchical measure of it even if the disclaimer applies: many saints' bodies did corrupt and that can't be held against them. But I don't think the opposite is true - i.e. that unholy people's bodies were saved from corruption (short of natural conditions that favored it).
There is a line in Scripture about the death of his faithful ones not undergoing corruption and I love that there is a tease of this in the bodies of His saints. It's the closest thing we can see to looking at another's "report card". One saint, an excellent preacher, had his tongue preserved. The rest of his body didn't fare so well, but it's almost as if God's sense of humor is being exhibited: "this fellow spoke of me so well that I preserved his tongue."
Imagine, for a minute, what it would be like if most people's bodies did not corrupt. That holiness was so widespread that you'd be embarrassed if your body DID corrupt? That twould be poor motivation for wanting to be a saint but I remember Camassia saying that embarrassment is the great dread of moderns; in Twomey's book he says that "respectability" became the chief goal of the Irish after they lost their language and started to become assimilated by the English during the 19th century.
Safety in numbers is dubious in light of Christ's words about the narrow way. The fact that 99.99% of our bodies will experience immediate dissolution soon after death is small comfort. Of course all of this begs the point and looks at things from the sinner's point-of-view. Following Christ is for His glory and not ours. The point of incorrupt bodies is to reflect that. It's a sign of intimacy between Him & his beloved, that he recognized that they really did sought Him & knew Him, but the real reason behind it is to give the rest of us a message. Incorruptibility points out what is possible not only in terms of bodily decay or lack thereof but in terms of intimacy with God.