Why is ebay so bad at handling feedback revision? Why is the estimated postage timeframe so short?

[ecoins.australia]

Seems the estimated delivery time eBay allows for postage is unfairly short. This ensures that your top rating will eventually disaperar.

Such a low late postage rate of 5% late deliveries means it is near impossible to keep a top rating. Are weekends and times after 5pm when postal services close in Australia used in the timeframe for postage estimates?

[kopenhagen5 · Accepted solution]

Many sellers now add another 2-4 days onto their handling time so the items arrive within the deadlines.

The times are supposed to be business days but often seem as though they don't consider public holidays.