The right to exclude is the same in both instances but the facts of each individual case matter. In the case of a landlord-tenant relationship, the landlord’s rights are still dominant but the tenant also has rights which compromise the landlord’s rights to a certain extent by a contract agreed to by both parties. Some jurisdictions may also have additional tenants rights enshrined in law, but generally speaking, if a landlord wants to evict, he is going to be able to evict. If you buy a house you intend to move into from someone who has rented the property out, barring some contractual reason you can’t that would be disclosed in the purchasing process, you’re going to be able to evict that family and move in once you own the house.

Social media companies don’t lose their right to exclude by having allowed you to sign up and use their services. They can still exclude you (read: ban you) pretty much at-will subject to their terms of service (so pretty much always at-will) and it’s not disingenuous to point out that yes, this is in fact their right as the owners and operators of the service.

Other service providers the facts may be different. If you have a contract with a service provider, you have a lot more in your favor under a negotiated agreement than the people that clicked “I Agree” the last time a social media company changed their TOS.