As a young professor, I wrote a grant proposal and took it to a senior theory professor for comments. He told me to take out the line "The ultimate goal of computational complexity is to settle the P versus NP problem." He agreed with the line, he just said that if we make these claims to the NSF then what happens after someone proves P different from NP? Nothing left to fund in complexity.
There was precedence here. In the 70s and 80s algebraists had the great goal of classifying all the finite simple groups. Once they were done, then what? Other examples are sending a man to the moon in the 60's or having a computer that beats the best human chess player.
Having an ultimate goal can be very motivating but quite limiting if that goal is actually reached. Luckily for us the P versus NP problem is a goal which will not likely be reached for a very long time.