What is being described here is not attack rate but attack time.
Rate is units per unit time: seconds-1
Time is, well, units time: seconds
The unit of the value on the character sheet in demigod is time. 0.7 of what? Seconds. It's 0.7 seconds for each attack, so it's attack time, not attack rate.
Really, it would be better if the character sheet did show attack rate. It has a very simple relationship to dps, attack damage and speed modifiers. You might have noticed that: what is speed? It's an x per unit time again. How fast is something is a rate. Easy mathematical relation, easy understanding. 10% more attack speed is a 10% higher attack rate. For attack time it's the inverse of 10% (~91%) of your old attack time.
There are many more examples. Rate should be what is shown on demigod's character panel.
(covering my ass here: Rate is not just with regard to time. It can be a ratio between any kind of value)