IMHO it should be illegal to force consumers to have an infinite spending limit on a post-paid service with consumption charges. If I want to cap my unpaid expenditure at any amount, I should be legally entitled to do so.

How many real applications actually want this behavior? AWS is not built around hobbyist needs. It’s built around being a platform to run most shapes of production use cases.

You can set up cost-based alerts (actual or forecasted) that send notifications via email or SNS. Based on this you can set up automations, such as applying an IAM policy to prevent further resource creation, shut down resources, etc.