Indeed. It should be common knowledge that shared platforms work because the company can make assumptions about load patterns and provision resources accordingly. Some might call that fair use, others overprovisioning.

Mining crypto under such a cost structure would force other users subsidize your buttcoins. Personally I wouldn't feel too happy about such an income transfer.

> transfer the costs to the customers (for example for excessive IO, energy consumption,...)

That would be fair, but enabling it might have costs beyond the plain consumed resources: io/cpu/etc schedulers that take the exceptional loads into account and mitigate performance impacts, metering and other business overhead, productisation, investments into all that, etc.