Burning 50% of the author rewards looks high but if you consider the SPORTS token supply and which post dominates here in number, it makes perfect sense. Reducing the supply and creating more demand can be a blessing. At first, it might feel bad when someone sees he/she gets 50% less rewards for a non-native post, but when SPORTS tokens price goes up, everyone will be happy.
Now SPORTS price is going up, who is not happy about this? :)
Like you've said, seeing a rise in SPORTS due to reduced token circulation is a win win for all. What's the point of earning so much when they ain't worth anything tangible?
That's the point! :)