You can trigger your own EXP event by finishing the Temple of the Demon God for about 10%.
There were also drops only and exp only events for the year. Check out the not so recently concluded Banquet Event and Memorial Day(?).
If I may express my opinion, the hidden meaning why both EXP and Drops are activated at the same time is to boost player activity for the server. Greater player activity is always beneficial for the server.
For example:
During upgrading events, most shops and players were selling items/materials related to the event (Ores and Over-upgraded items.) and you can expect the same with exp and drop events.
In the end, it boils down to a matter of choice. You can always go VIP or pop a manual with whatever you would want to pursue.
Also, We are free to express our opinions the same way that you are free to suggest. (Though some may be a bit ...... yeah)
I know that you may not want to choose one but we always do.