Because the vast majority of complaints are likely to be frivolous.
How do you know this?
I am not sure what you mean when you say that the "ratios didn't work" when you were denied boarding in your own case. Was this a frivolous complaint or was this a situation where you were automatically entitled to a refund anyway?
Why did you have to write to them? If you were denied boarding then they should be contacting you. They had all your details.
If you are automatically entitled to a refund it will come out in due course. So maybe filling in the online form once is sufficient . How long should a person be made to wait in this case incidentally?
If it is not a cut and dry situation then you might want to follow up to see what is happening. Why should you have to input your flight details. name & address, details of other passengers travelling again and again and again. Once should be enough. One reference number should be enough. Instead they give you a different reference number each time.