Your free-market at work!
Actually, the transition make quite a good bit of sense. Sabra, one of the hummus larger producers in North America, has a factory in Virginia. Currently, most of the chickpeas going into their production line are coming from the Pacific northwest. It makes sense for them to encourage more chickpea production since it has the dual benefit of reducing shipping costs AND mitigating their risk of a bad chickpea season by sourcing from different regions.
On the farmer side, and I hate to say it because I love my tobacco, is that tobacco is a shrinking market (esp. with the continuing decline in cigarette usage - which, as we all know, is the real driving force behind the economics of tobacco growing), while hummus consumption, and the need for domestic chickpea production, is growing in the U.S. everyday. Better to grow a crop with a growing market, than a crop for a shrinking one. Supply and demand at work!
On the other hand, most Virginia tobacco does not actually come from Virginia. Within the U.S., I believe, most domestic production of Va tobaccos is out of Kentucky. Additionally, while the number of acres of tobacco under cultivation in the U.S. might be dropping, places like Africa and China are increasing amount of tobacco growing every year.
Furthermore, since historic driver of the tobacco market in the U.S. has been cigarette production, I would hazard the guess that the loss in cultivation of tobacco is associated with the specific types of tobacco that are associated said production - namely, a specific strain of high-nicotine Burley. I would guess that production of other tobaccos, like the ones favored by pipe and cigar tobaccos is remaining steady - if not increasing to meet the demand of a growing market segments.
I highly doubt that this market correction in tobacco production is the signal of the extinction of tobacco as a consumer product, especially of premium products like pipe tobacco. It's true that you might see some tobaccos, such as certain orientals become more scarce, as long as their is sufficient consumer demand, they will continue to be produced. Anyway, IMO, what you see here is the death knells of the cigarette as the dominate form of tobacco usage in the United States - frankly, cigarettes are terrible in from the point of view of both the tobacco connoisseur and the health advocate. (full disclosure: I was a cigarette smoker, and yeah they are terrible.)
Moral of the story - don't morn the passing of pipe or cigar tobaccos - celebrate the end to cigarette dominance!