I totally agree that the current resting system is hurting some classes a lot more than others.
The Warlock is a "short rest" class, and is designed by WoC around this idea. They get very few spell slots because of this. Fighters too are balanced around the short rest.
Wizards and Clerics are designed around the long rest, and only regain powers then.
DnD 5e is at it's core a game where you are supposed to have several sort rests before you take a long rest. The Long rest is "end of the day". Not taking this into account because it's "difficult to implement" etc is a bit silly. Right now there's no reason not to long rest after each encounter, but it makes my Warlock seem a lot less effective than my Wizard because of it. (The Waclock in effect only has 4 spell slots...)