A salary cap can also help to control the costs of teams and prevent situations in which a club will sign high-cost contracts for star players in order to reap the benefits of immediate popularity and success, only to later find themselves in financial difficulty because of these costs. Without caps, there is a risk that teams will over spend in order to win now at the expense of long term stability, and team owners who use the same risk-benefit analysis used in business may risk not just the fortunes of their own team but the reputation and viability of the whole league.
Sports fans are generally looking to support a team for life, not just a product to purchase for the short term. If teams regularly go bankrupt or change markets the same way businesses do, then the whole sport looks unstable to the fans, who may lose interest and switch their support to a more stable sport where their team and their rivals are more likely to be playing in the long term.