There's a lot of things that can be said about the Enterprise-D's design, but it doesn't look generic. I'll take the Enterprise D's curves any day and twice on Sunday over the E's angled flatness.
The Enterprise-D has a timelessness to its curves that later designs have just lost. Why are there so many impulse engines now? why are there so many angles and widgets and extra vents on the nacelles? Why have these darker panels and ridges and steps on the saucers in particular? What does that get you over the sleek minimalism of the Galaxy-class? These things aren't speedboats or gunships. They don't need to look fast or look powerful to be fast or be powerful – the fastest and most powerful ship in the entire galaxy is a giant bloody cube for god's sake. The Galaxy-class looks ambitious, and assured, and advanced. It looks like a repudiation of a more narrow militaristic mindset, whereas the Enterprise-E looks like an embracement of it.
And even the interior is more memorable to me. The D's bridge is two levels with the horseshoe, where the E's is a single level and more closed-in.
Oh god, this, 100%. One thing I've NEVER liked about the Enterprise-E is its bridge. It's just a very generic circular "Star Trek-y" bridge, and the only character it has is all those weirdly shaped downlit steps everywhere. The Enterprise-D bridge is incredibly distinctive, with an actual design ethos behind it.