That is simply not true in my experience. The N900 screen is neither blurry nor barely responsive to finger touch. But the hardware is / was not the most interesting point about the N900 anyway.
I don't have any experience with Nokia devices other than the N900 so I can not comment on the N770. But I remember reviews from the time the N900 was released were the touchscreen was not really praised but commented on as much better than other resistive screens.
Also there are 4 years between the N770 and the N900. There is definitly no glare on my N900 screen - to the contrary, it is readable even under direct sunlight (without any backlight) because it is transreflective.