Windows of time for playing?

Who at Riot decided that we the players would enjoy playing certain aspects of the game for only limited periods of time. RGM is only on the weekends. With the new 3v3 Ranked changes they too will have only certain time windows to play in. Smite has a RGM for every single DAY of the week. With a smaller player base ive been told also. Overwatch a game that released recently has a Weekly Brawl mode for an entire week. Not some hours on a weekend. Is Riot just lazy or is it really trying to force players into Dynamic Que that badly?