Hosting credits are not currency. Most startups will never need anything close to $5000 in AWS credits.
Not to mention that AWS basically gives them out like candy. I have several grand in AWS credit just from attending hackathons and conferences.
This statement is not true. It is quite easy to have a $5,000 a month bill on Amazon.
The majority of startups never get any real traction and see only a small trickle of traffic every day.