Hypocrisy
It is a little sad that hypocrisy is considered to be a far worse thing than at least *attemping* to make a moral stand. It is seen as far better to be totally amoral, and to take no stand at all. (thankyou, Diamond Age. Go read it if you haven't).
I'll eat veal and foie gras, but not battery farmed chicken, for example. OMG hypocrit (sic) you might say, but factory farming is not only a far, far more unpleasant process than the production of either of those two, it also produces decidedly disappointing products.
If the PETA boss does manage to improve the lot of cute animals across the world at the expense of a few litres of insulin, then she's done well. Attack PETA because of the stupid things it does (there's no shortage of those!) but not because of the proclivities of its management.
The problem is that we demand far more meat than is practical to farm in 'nice' ways, and we demand it at a cost which is rather impractical to sustain without these rather unsavoury production methods. Moreover, the production of meat is quite inefficient, enerywise, compared to growing edible crops on the same land. Historically, you'd farm animals on land which could not be used for grains or veggies. LIvestock can process grass into things which are actually nice to eat after all.
If synthetic meat becomes practical, thats great. The world could benefit from cheap and widely available protein, and all sorts of less desirable farming practices can be stopped. But what are the chances of s'meat being a) cheaper b) just as nutritious c) actually accepted by consumers (its far more deserving of the label 'frankenfood' than GM wheat, or whatever) and finally d) being less destructive to the environment?
Pretty slim, I'd say.