Its not they let it happen, its the fact that it designed to happen.
These companies use highly automated services, if the approach feels inhumane then you are noticing the fact that it is inhumane.
Its not a malicious act for these companies to do this, its a by product of a set up circumstances that are designed to trigger a response to catch people abusing the product.
Naturally a person from time to time will trigger the automated response and appear to use as a cruelly treated victim, but what you don't see is the thousands of other people that systems like this catch. To them the system works extremely well, innocent victims here and there included.
Why it appears to suck is what is mentioned above, users are not customers, you are a product being sold. Hence they want to spend the bare minimum on user support, they want to maximsie the profit per product. On a personal level they have no interest in you.
Like a farmer to cattle. You have to treat the cattle well enough so you have sell it, but the farmer has no personal attachment to a cow as such (pets aside), they are just a product. To keep a cow healthy sometimes you have to spend some many on vet services, but you don't bring in the vet to inspect every cow, thats bad business.
Google has great customer support by the way. If you want to spend large sums of money they will send a man to company to discuss exactly how you spend it.