If u check here :
301 Moved Permanently 301 Moved Permanently u will see that we have upgrade/meld/xp etc events once in a month (give or take) of every kind of those events.
Additionally there was the event of happy hours between 10-12 October during of which there were 2-3 more jewel related events of ea kind (remove-fuse-meld), along with double xp/sp events.
So what do u mean by saying "I spend weeks on many toons barely playing the game because I have to wait for jewel melding/upgrade events that rarely ever come."? Once in every 4 weeks doesn't seem rare.
Besides that's imo the meaning of 'event', if we have every week or every other week a jewel or upgr weekend, then it's not an event, it becomes more like regular game and market would be flood with jewels after fusing or with gears high plussed after upgr events.
Let alone that u may need jewel and upgr but others may need exp, sp, or pet exp or double gold/drop events. And as a month has average 4 weekends, as it seems to me events must be spread along accordingly to satisfy every one's needs