I don't want to suggest that there is anything wrong with new world wines (or Italian or German wines either). For me, the issue is that there are so many wines available, and it is unreasonably difficult to work through everything in order to decide what I would like. It could also be very expensive, and might cause wine-drinking to become a problem rather than a pleasure. So I know a little about French wines, and I know what appeals to my palate, and that's enough for me.
I divide my wine-buying into two categories, vin de table and bons vins. For vin de table, I tend to buy 10l boxes -- very good value for money, and also good weight-to-product ratio, as the box weighs very little. I bought some boxes at about €20, which is roughly equivalent to €1.50 a bottle. The bons vins averaged about €8 a bottle: that's not dirt-cheap, but we are talking about fairly good stuff. The real value of buying bottled wine in France is that you get much better wine for the money.
I suspect that Californian, Australian, and Chilean wines are less good value simply because of the cost of shipping them such vast distances.