Those with land or other capital will come up with rationalizations of why they can't share the resource. Let's focus on land for now. The owners will point out, correctly, that the dispossessed have no land management skills, while the land owners are good stewards of the land. That the masses will simply trash the land if it was made available to them. That the masses are too lazy to be productive and responsible. They are correct if nothing else changes--most people (including land owners, as history shows) do not have the knowledge or ecological values to be good land stewards. Most people (including landowners) will look for the easiest solution to a problem, the one that minimizes work for them in the short-run, unless they are inspired by a higher good. The commonly accepted solution is to deprive the masses of land and keep them powerless and distracted by boogiemen such as politicians, corporations, government and advertizers, or carrots such as houses, cars and money. Another solution (one that few landowners, whether they are environmentalists or not, are likely to try) is to offer free land to the masses, but in conjuction with training, not just in ecology, but in industry (of the low-capital, craft type). And along with training, create a local economy which gives access to tools and materials to anyone who wants to participate and be productive. There has to be some discretion in who can join a land-based collective enterprise, but today most people who want to work the land are earnest and hardworking and should be given a chance. There are other factors that might interfere with someone's capacity to work with other people (too much ego for example).
The latest bout of environmentalism and interest in farming might be a smokescreen to keep the status quo, as it comes mostly from the owning class. Land redistribution solutions such as those advocated by Henry George have been subverted by the owning class so that land for use and production is even more out of most people's reach today than it was in Henry George's time. Land is available, but at the cost of indenturing most people who would buy it.
People who own land are either unaware of the option of sharing it, or afraid to. There are good reasons for the fear, besides the one mentioned above--loss of autonomy, conflict, and waste of time in meetings are real possibilities. But for each of these difficulties, solutions already exist and new solutions are waiting to be found.
Loss of autonomy: some loss of autonomy may be unavoidable, but not all autonomy has to be lost. In making decisions, retaining some autonomy can be achieved with any decision making model that gives everyone a voice, does not concentrate power, is local, and encourages deep listening and respect. Deep consensus, sociocracy, holocracy are possibilities I know about, and there may be others. As far as doing things, if people collectively made their basic needs, there would still be time for individuals to pursue their avocations without too much group involvement.
Conflict: there have been numerous conflict resolution technologies developed, such as NVC, Zegg Forum, Nakaima/Heart of Now. There have been numerous conflict prevention technologies developed such as folk dancing, playing music together, singing together, storytelling, sharing yoga/chi gung, skill-sharing and knowledge sharing workshops, rituals. Inner (individual) spiritual work and common vision are helpful. Romantic/sex partners (especially for young people) can help relax people. Good balanced work and connection with nature. Good decision making also can prevent conflict. An atmosphere of agape.
Waste of time in meetings: Good meeting faciliation skills and training in whatever decision making the group chooses are antidotes to time waste.
There are better reasons for sharing land than not sharing it, especially when the fears for not sharing have been calmed. Those reasons are:
1. It is the ethical thing to do, since the earth is a common treasury for all--just because your ancestors benefitted from stealing and murder of the natives who lived on that land, doesn't mean you "own" the land.
2. It is more joyful to work the land and celebrate with others sharing a common vision.
3. It is better for the children to have playmates close by.
4. It is more efficient due to economy of scale (I will say more about the deeper reasons for economy of scale in a later post) and to specialization.
5. It is good for one's ego to serve others and not always get one's way.