Forcing an employee to wear a necktie is wrong for the following reasons:

Neckties Are Uncomfortable:
Some people find wearing a necktie very uncomfortable. Since employees should have the right to be comfortable in the workplace, they should not be required to wear a nonessential, uncomfortable article of clothing.

Neckties Promote Gender Bias:
Those workplace dress codes that require only male workers to wear a tie are blatantly sexist and gender biased. What really irritates me is when a female manager insists that a male subordinate wear a tie when they themselves are not required to wear one.

Neckties Promote Cultural Bias:
Most US business managers trip all over themselves to ensure that cultural diversity and tolerance is promoted in the workplace. However when it comes to corporate dress codes, managers require that male employees must conform to their Western European ideals and wear a necktie.

Neckties Promote Class Separation:
The tie becomes a symbol of class separation in work environments were only the professional or managerial titled male employees are forced to wear a tie. The tie then becomes a symbol of authority and control to many of the non-titled workers. If you are trying to create a team out of your employees, visible symbols of status and hierarchy should be avoided.