It gets even better than that if you're in an approved accelerator / incubator: you get $60,000 USD in hosting credits, at a rate of $5,000 a month. We're entirely hosted on Azure using their Linux VMs and have had a great experience with them so far.
I think the reasoning is that if you convince an accelerator/incubator to accept you your product has a higher chance of succeeding. This will mean that the chance of you still existing (and starting to pay) after 3 years should be significantly higher.
Many companies have discounts that they can afford to give, but they make it a bit of a hassle to get them, so the bulk of customers keep paying full price but they can also retain the miserly customers at a reduced profit margin.
For example, some food retailers publish discount coupons in newspapers, so the discount is only available to people willing to go through the hassle.
