Using simple stat weights is really problematic with how gearing works now in WoW. They can’t rank gear in 5 of the slots (head, shoulder, chest, trinket 1, trinket 2) and don’t work great for weapons either on physical damage specs.
If you want to enter in stat weights, you have to start with the report from a custom gearing strategy. There is an option to change it to stat weights, and then you can mess with the stat weights that were created or enter your own.
We do it like this because then we have at least something that can be used to rank the trinkets and azerite items. Otherwise there would be no way to rank all of that and the optimizer wouldn’t be very useful.