I think it's important to keep in mind that at the rate Ayu releases music we're bound to get some duds in one category or another. Even in the past we've gotten boring PVs like daybreak or disastrous covers like (miss)understood. I think the reason she can't give every song the same creative energy is because at some point it becomes too much so we don't get everything at its full potential.
Now the other alternative is that she slows down her release pattern and only releases music when she's truly inspired to make something incredible. This is a great idea in theory but I think Ayu fans would jump off a 10 story building if they had to wait for music like Utada fans for example.
We all know Ayu rarely takes her time with things, it's in her nature to keep going and going and going and yes sometimes her creativity suffers. But if it's getting to the point that you cannot enjoy her music anymore then and it seems like she's constantly disappointing you, as much as people hate it when others say this, it's time to move on. Let her go for a while or permanently. Or just accept the good with the bad. She's not perfect and everything she does won't be perfect that's why I prefer to see her as a human being and not an entertainer because I don't feel the disappointment of what could have been or what should have been for things like covers and PVs. As long as her music is good, I'm good.