hmm, what I got out of it was that it was concerned that SF/F in particular seems to encourage these cliquey sub-genre groups that claim to be the One True SF (or Fantasy) and all the others are commercialised market-driven trash. The author was suggesting that, as members of a literary genre that is scorned by the 'mainstream' literary world it might be better to bury their differences and get on with the business of writing, reading and enjoyment.

The thing is, when groups feel like they're a besieged minority, instead of turning to face their attackers (in this case, the 'mainstream' literary community), they tend to engage in bitter, pointless infighting, thus giving their detractors more ammunition? Does that make sense?