He says that Voyager had relatively static characters. That's only partly true. Chakotay, Kim, Tuvok didn't change that much, but Janeway (from a newbie captain, a bit overmilitaristic to hide her own uncertainties to a captain and community leader who feels mostly at ease in her role), Neelix (changes from cynical cheater to dependable crewmate), Paris (from ladies' con man to loving husband ), B'elanna (from angry young girl to someone who gets better at accepting others in her life), 7 of 9, and the EMH (these last 2 are very obvious) all change significantly - that's the majority of the cast (not sure on Kes - I saw some change but she stayed only three years).
He also says that the same is true in TNG - mostly static characters. I agree on that. Though Picard changes over the years.
Then he says that at least the TNG characters were strong whereas the Voyager characters are not. I think that's also debatable. In my view, on Voyager Janeway, 7, and the EMH rate as 'strong' characters, Kes, b'Elanna, Tom, and Tuvok as mid-tier, and Chakotay and Kim as weak. On TNG, I'd only call Picard and Data really strong characters, I'd put Riker, Geordi and Worf, as mid-tier (though with several strong outings), and Beverley and Deanna generally as 'weaker' characters though they too have some strong episodes.
So on the face of it, Voyager doesn't come out weaker than TNG in my view in these respects, even though I usually see TNG as the better series. However, voyager is 7 years younger and viewer expectations had moved on, whereas Voyager tried to stick too much to the 'old' format which I think has been its bad fortune.
One flaw TNG had that Voyager doesn't have in my opinion is that it could take itself too seriously sometimes. Voyager knew how to make fun of its own premises and also how to make believable how a sense of family grew between the crew over the years.