"Why lower the bar?"
Because of the chance of misundertanding. Failing at acknowledging artificial general intelligence standing right next to us.
An incredible risk to take in alignment.
Perfect memory doesn't equal to perfect knowledge, nor perfect understanding of everything you can know. In fact, a human can be "intelligent" with some of his own memories and/or knowledge, and - more commmonly - a complete "fool" with most of the rest of his internal memories.
That said, is not a bit less generally intelligent for that.
Supose it exists a human with unlimited memory, it retains every information touching any sense. At some point, he/she will probably understand LOTs of stuff, but it's simple to demonstrate he/she can't be actually proficient in everything: you have read how do an eye repairment surgery, but have not received/experimented the training,hence you could have shaky hands, and you won't be able to apply the precise know-how about the surgery, even if you remember a step-by-step procedure, even knowing all possible alternatives in different/changing scenarios during the surgery, you simply can't hold well the tools to go anywhere close to success.
But you still would be generally intelligent. Way more than most humans with normal memory.
If we'd have TODAY an AI with the same parameters as the human with perfect memory, it will be most certainly closely examined and determined to be not a general artificial intelligence.