What it comes down to is people tolerating a badly designed mechanic for the sake of its novelty. But I think we can reach some consensus on the pros and cons at least
Pro:
- Unique mechanic distinguishes it from other casters
- Limited spell slots encourage creative use
- Big nova potential
Cons:
- Unique mechanic can be complicated to move to/from other casters, especially for new players
- Doesn't play nice with multi-classing, including abusive uses of other classes features
- Limited uses at max power discourages utility magic or nonscaling effects and guides towards nova use
- Highly dependent on DM giving short rests, so much so their power level fluctuates wildly depending on how often you get them.
For me, none of the pros outweigh the cons. So even patching the multi-classing drawback still leaves me with a system that encourages me to save my slots to drop my highest level effects at boss fights.
Maybe if they can fix pact magic so that it's more intuitive for new players, isn't dependent on short rests, isn't prone to multi-class abuse and doesn't prioritize upscaling fireball over using shield, I'd be ok with it. But any such fix will either come at rewriting pact magic anyway or bending other rules around it to make it work. IMHO, neither of these solutions are as simple or elegant as just using the existing spell system every other caster in the PHB uses.