@BVI. They are concerned about looping, and infinite loops (not to be confused with Apple's Head Office which is at Infinite Loop drive).
It is very easy to make an infinite loop, so they have set the limit at a max of 10 per any 1 second period.
They don't all need to fire at the same time. For example you could have Actions/ Webhooks in Table A that says to create a record in Table B when a record is created in Table A. Like a mirror record. But then you could also have the opposite setup to create a record in Table A when a record in Table B is created. So those are actually firing sequentially but would fire infinitely and create millions of records pretty quick. So they set that sanity limit of 10 per 1 second elapsed time.