I think you have this exactly right. If exotic landraces were so awesome, we'd all be growing them, instead of hybrids. The fact is not only are they NOT "awesome", in most respects, they're exactly the opposite, namely difficult to grow and unrewarding.
I'm not even sure there is really a "landrace craze" but to the extent there are noises like this, in my opinion its mostly hype and misunderstanding, much of which is deliberately promulgated by the ones selling se-eds. Some of this may be false nostalgia for a time when things were supposedly "pure". Everyone has heard about the awesome "grass" of the disco era, but I think that's a case of things looking better from far away. The reality is that the vast majority of 1970s era outdoor grown landrace weed was leafy seedy schwagg that makes today's brown Mexican brick look great in comparision. There was great landrace stuff out there in the 1970s, but it was super expensive, and most markets and smokers never saw ANY of it.
So along those lines, yes, there are some "great" landraces that are famous and absolutely excellent: Santa Marta/Columbian Gold, Punta Roja/Panama Red, Afghani Mazari Shariff, Oaxacan, Jamaican Lamb's Bread, some African ones like Malawi, Durban Poison, Swazi, etc. All of these are rightfully internationally known based on their quality. But again, all of these are already available commercially, in many cases from more than one source. If you want to grow these, you don't need Arjan and his glory-seekers to take them into a marketplace where they already exist.
As to the more obscure landraces, the fact is, that most of these don't exist in the commercial marketplace not because nobody has heard of them, or because they're so hard to get, but rather because they're simply unexceptional. A lot of these really aren't much better than "schwagg". Love him or hate him, but breeder Reeferman (who is known for his landrace work), said he spent several years tooling around Central and South America looking for unexploited landraces, and couldn't find ANYTHING down there new that he thought was worthwhile.
While I'd say its *possible* that there are still a few "hotspots" left on the planet that have decent unexploited landraces, it highly probable than none of them are any better than what's already out there. How are you going to beat something like Mazari Shariff which was selectively bred for 1000 years into the most renowned hash-strain on the globe? Or Santa Marta which was derived from a famous 300+ year old line brought to Columbia by Simon Bolivar? The chance of Arjan and crew wandering out of some god-forsaken hellhole with a spectacular new landrace better than these?
Zero point zero.
To answer the question, why would you want to grow these if you're not breeding? Well *IF* you happen to be located in a geographic location similar to their natural habitats, then it could make a lot of sense to grow these outdoors. So, for example, if you were growing in Central America or the Columbian Mountains it would make sense to grow Santa Marta or Punta Rojo, two excellent lines highly adapted to those conditions.
Some people do grow these out of pure nostalgia or curiosity, just to recreate something they tried (or wanted to try) many years ago. (I don't think it qualifies as a pure "landrace" but this was part of the motivation behind me growing out some Mexican commercial "schwagg" sativa; you can see the results in my grow report below). Some people just grow these for the pure technical challenge, just to say they did (why climb a mountain?), or just to have something unique.
For anyone else? Not only are most landraces NOT a good choice, for most modern first world growers they're a BAD choice.
Sure the equatorial sativas may give you great taste and effect, but these types of plants are totally unsuited to indoor cultivation. They typically stretch like crazy during flowering, making it hard to control height and to light them evenly indoors from fixed light sources. Some of them will continue to grow throughout the entire flowering period. These typically take a long time to finish flowering (in many cases over 16 weeks), far longer than modern hybrids. In some cases the flowers are leafy and offer relatively low yield, and almost all of these landraces put out lots of hermies. Yes its possible to grow these indoors, and plenty of people do it, but the sativa-based hybrids are a lot easier to manage and will usually give better results for almost everyone. Outdoors, these sorts of sativas simply won't finish flowering in most of the USA or Europe before the winter frost comes in and destroys the plant. Again, yes, if you are in a really Southern location (eg S.Florida) you might pull some of these off outdoors, or if you can shelter them in a greenhouse, but most growers don't have these luxuries.
On the indica-landrace side, yes, you can grow those indoors if you like, and plenty of people do. These also can have their disadvantages, for example, most of these plants like dry weather and are prone to rot in humid indoor grows, or in humid North American falls. Many of them also aren't particular tasty. But some of these are good and for example Hindu Kush and Afghan #1 are relatively well known and popular landrace indicas that people like. But again, the best of these subcontinental lines have been around in commercial se-ed for for decades already.
