Most are written to protect the landlord against anticipated issues of contention. Some leases are more favorable to the landlord than others. In almost all cases, most terms and conditions contained in a lease document are negotiable. The time for negotiations and review is before a document is signed. Often clauses that later may impact a business or individual could have been excised during negotiations without conflict.
Timing is important.
There is less likelihood of a clause being modified or removed when it has an economic impact on the landlord. For example, some leases contain a clause that allows a new landlord to evict a current tenant under certain specific conditions. This clause is intended to provide a new owner flexibility. This clause is not in the best interest of the tenant. A tenant works to establish a customer base, develop a reputation, and may invest in improving the location.