TNG is more of soap opera than an action series. And even tho i would be the first one in line at the opening day of tng movie..it shouldnt be there. Its like putting the day time soaps on the big screen, it just doesnt belong.
I think there's a fundamental truth in this. Some things just can't be shoehorned into being something that is essentially against their nature. TNG was kinda long form. It was a tone poem, a fine wine, something that needed a certain degree of reflection to appreciate. TOS was much more immediate and visceral. It makes sense to me that TOS could fit the "popcorn movie" label like a glove, but TNG basically fails because the characters/format are not suited to it.
The TNG cast might have worked really well in The Motion Picture.