I think yes and no.

Landscape photography is intrinsically an individual art form, and field landscape photography is frequently most productive when pursued solo. Add the LF aspect to it, and a largely solo activity gets even more so. Lots of photo workshop pro's, photography guides, etc. have told me that mixing LF photographers with other format shooters frequently results in rather spectacular conflicts (LF shooters are too slow, hog the best spots for far too long, etc.). I remember focusing my 4x5 at the Santuario de Chimayo shrine near Taos, and getting yelled at by a bunch of tourist photographers on a tour bus for hogging the best photo spot, being selfish and inconsiderate, etc. A few run-in's like that and you learn that landscape photography is often best pursued when few or no people are around and the potential for conflict is minimal. So certainly landscape photography requires individuals who can tolerate a certain proportion of alone time.

I think if one abstains from LF, then field photography gets much more social. Large workshop groups of DSLR shooters seem to have a grand ol' time, and work so quickly that no one gets in the way for long. But it is difficult to generate portfolio grade work that way. For these folks, photography is primarily a social outlet, and there is certainly nothing wrong with that.

But I wouldn't go so far as to generally categorize field landscape photographers as loners. Certainly some of them are. But you also meet many interesting people while traveling. And if you want to have that spectacular landscape photo on the wall, you have to work very hard and make sacrifices. And spending some time solo in the field is one of the sacrifices, as is spending boring hours driving, in motel rooms cleaning gear and loading film holders, etc.

After I retired I considered taking on pursuits I had studied in college, namely writing books/short stories, writing music, etc. But these too are largely individual art forms; they require a lot of solo work (albeit mostly at home); and they require a lot of sitting (not a good thing as you get older). The advantage of photography is that it gets you out into the wide world and is a great source of exercise.

For me, the best part of photography is sharing prints with family, friends and other photographers. The feedback and positive reinforcement I receive helps motivate me to generate even better work, and to put up with some of the bumps in the road I encounter as part of the process.