I don't think that's true for everyone here. We have a fairly large contingent of social conservatives on FR, and they range across a spectrum themselves. Some of them are so holy that they can condemn other people for having an impure thought, let alone gambling, and they can be absolutely sincere and serious about it. That's a minority, but they do exist.
I suspect the rest of Bennett's critics are more like the example you cite. They just don't like the guy, and they perceive gloating over the random misfortunes of one's enemies as a lesser evil than gambling. I'm not sure it is, but I'm not that kind of expert on sin. My expertise is in applied sin.
Now THAT's funny!
And to quote you, if I may:
They just don't like the guy, and they perceive gloating over the random misfortunes of one's enemies as a lesser evil than gambling.
I'm no expert on sin, either, but I know your statement is correctly summed up by this word:
schadenfreude \SHAHD-n-froy-duh\, noun:
A malicious satisfaction in the misfortunes of others.
That pretty much sums up many of his detractors, here, yes? ;)