Doesn't have to be selling the site. I guess Bondware would want to showcase their software to potential buyers, and Renderosity is proof that the software can support a rather large community - despite all our bitching it works fairly well.
Totally filtering out all nudity would mean the site looks smaller than it is. And in-your-face nudity in the thumbnails is not a good idea when trying to convince a potential client.
Agree with pjz99: if this is the case, just say so. It's a valid business reason.

The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter

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