Opposition to the spoils system primarily stemmed from concerns that it allowed unqualified individuals to receive government jobs based on political loyalty rather than merit. Critics argued that this practice led to inefficiency, corruption, and incompetence in government, as positions were filled by friends and allies of those in power rather than by individuals with the necessary skills and qualifications.
The other points you mentioned—such as women's exclusion from voting, the restoration of tribal lands to Native Americans, or land grants for immigrants—are related to different social and political issues and do not directly address the primary opposition to the spoils system.