I guess that's fair. It is odd that the game jumps into character creation immediately. It's mostly a relic of AD&D's PHB, which told you to look in the DMG if you wanted to know how to play... but only if you were the DM! Really a bizarre choice, looking back.
144? That feels like saying "there are 444 weapon and armor loadouts in 5e D&D" because there are 37 different weapons and 12 different armors. Like a background in 5e takes a quarter column. They're not using 35 pages for backgrounds.
I guess Personality/Ideal/Bond/Flaw is out. Oh, well, they only brought the trappings from 13th Age and none of the teeth anyways.
More like because they were redoing all the core rules in the PHB and totally ran out of time. Time is a resource, though.
I'd like to see some of the tools that the 1e DMG offered. For all of its pretty numerous flaws from a modern perspective, the idea of what should be in the DMG was remarkably sound.
I don't care how many more there are; I just want them to be better designed. I'm happy with Kobold Press's stuff, and MCDM's stuff, but the Monster Manual has three major kinds of monsters: (a) sack 'o hit points and a stick, (b) sack 'o hit points with spells, (c) sack 'o hit points with legendary actions.