Final answer:
The AFL only allowed skilled craft unions to become members because it focused on representing skilled workers and improving their wages and working conditions through collective bargaining and strikes.
Step-by-step explanation:
The American Federation of Labor (AFL) only allowed skilled craft unions to become members of the organization because it focused on representing the economic interests of its members, which were primarily skilled workers. By organizing skilled craft unions, the AFL aimed to improve wages and working conditions for its members through collective bargaining and strikes. Furthermore, the AFL believed that combining workers with similar skills and trades would be more effective in achieving their goals and protecting their interests.