I think they are kind of a fad. I think people want something the neighbors don't have to help draw in deer. Deer do apparently like them and they provide variety.
They don't produce a lot compared to acorns...maybe they produce sooner I'm not sure. I have tried to grow them with not much success but I am on the northern fringe of where they probably will grow.
I would not call them a fad. They can be an important part of a habitat management program. I will say that Dunstan chestnuts (a cross between American and Chinese) has really been over-hyped in the hunting literature.
History:
The American Chestnut was the dominant overstory tree in eastern forests for many year and the primary nut source for wildlife. A blight killed most of our American chestnuts years ago. Chinese chestnuts are resistant to the blight. Folks like Mr. Dunstan hybridized American and Chinese chestnuts to produce a chestnut that has more American characteristics but is resistant to the blight. The American Chestnut Foundation has been working toward hybridizing a strain of chestnuts that have a very high percentage American. There is also some recent GMO technology (not yet approved) that claims to make the American chestnut resistant to the blight.
Practically speaking:
American chestnuts tend to grow straight and tall and are a great timber tree. Chinese chestnuts tend to branch early and don't have the same timber value. From a wildlife perspective it doesn't matter much as long as the trees don't get blight or are able to produce nuts in the presence of blight. Chestnut Hill has branded the name Dunstan chestnuts and done an amazing job of marketing them to the hunting community.
Chestnuts can produce nuts much sooner than most white oaks and they are one of the few nuts preferred over white oaks by deer. They have a high carb content making them an excellent pre-winter food. Most tend to drop a bit earlier than most oaks. Many oaks can take 20 years to produce their first crop of nuts where a chestnut can produce its first nuts in a few years.
Auburn has patented several Chinese chestnuts with good wildlife characteristics. I believe they are now licensed to and sold by the Wildlife Group. If your objective is solely attraction, there may be a lot of other options to consider. If you plan to use chestnuts to feed your herd and part of a permaculture strategy, they are a great option for areas where they grow well. The problem is that unless you have deep pockets, getting enough volume of chestnuts to have a true food impact is impractical buying from the sources advertised to hunters. Chestnut Hill sells their trees through Walmart in many areas now and they can command upwards of $20 per tree. For this reason, many guys doing QDM are growing their own from nuts.
I started my permaculture project several years ago. I started with Dunstan chestnuts. One solid source for nuts is Chestnut Ridge of Pike County. Keep in mind that chestnuts are not completely "true to seed". That means that when you grow one from seed (verses grafting), the trees may not have the same characteristics as the parent tree (consequence of sexual propagation). So, when we talk about growing Dunstan Chestnuts from seed, we are actually growing some kind of hybrid chestnut that we are starting from Dunstan trees.
I found growing trees from nuts and seeds to be a great cabin fever project for winter. The setup cost is not low, but when you amortize it over multiple years and the number of trees you can get, you cost per tree goes way down (presuming you count your labor as a labor of love). Wbpdeer has focused on Chinese chestnuts and has developed a great deal of practical experience growing them in just a short time. I have transferred some of my threads related to growing chestnuts over from the QDMA site. Here is a thread from 2012 that got me started growing them:
https://www.qdma.com/forums/showthread.php?t=46975 Since they are closing the forum I don't know how long it will be available.
No Magic Beans:
There no magic beans when it comes to habitat management. Chestnuts can be an important part of a habitat management plan but they must be part of an overall strategy to be effective.
Thanks,
Jack