Why did the Duke of Alba's taxes face such strong opposition in the Netherlands?

The Duke of Alba’s proposed taxes, specifically the permanent 10 percent sales tax known as the "Tenth Penny," faced intense opposition in the Netherlands for several critical reasons:

• Erosion of Autonomy: The taxes were designed to be general and permanent, which would have provided the central Spanish government with financial independence. This would have stripped the separate provincial states of their ability to negotiate conditions for granting taxes, effectively ending the traditional privileges and "particularism" of the Low Countries.12
• Absolutist Control: The tax system was viewed as the final step in a policy of centralization and absolutism. By removing the financial leverage of the local states, the Spanish king would have achieved unlimited power over his subjects, undermining the independent status of the nobility and the authority of local governments.12
• General Discontent: The proposal united diverse groups—including both Roman Catholics and Calvinists—against Spanish rule. The aggressive enforcement of these measures, which included the arrest, torture, and imprisonment of officials who resisted, served to galvanize the rebellion and ultimately breathed new life into the ongoing revolt against Spain.12