I don't agree. While the scripts are certainly bad and that doesn't help anything, I still don't think they're the right voices for these attractions.
I feel Imagination worked best in its original form, or some variation of that anyways. I can't even begin to think of a new concept different from the original ride that could come anywhere close to properly capturing the essence of imagination itself like the original did. And I think the original ride would have still been a fantastic ride even today (just with a few minor plusses and tech upgrades here and there). Dreamfinder was a fantastic character, similar to Merlin in a lot of ways (including the voice). I don't think Eric Idle would make a good new version of Dreamfinder, nor can I think of any worthy replacement ideas for the pavilion that he would fit properly in.
Even if the current concept of Imagination had been given a better script and taken to its full potential, it's still a bad core concept and wouldn't have come close to capturing the true spirit of Imagination like the original ride did.
Spaceship Earth works best when it's a sweeping and epic experience. Intellectual, philosophical and almost trance like. Jeremy Irons got it perfect. His was a really soothing and otherworldly, yet epic and sophisticated voice and performance in addition to an incredible script. While the new script is certainly terrible and intellectual vapid, Judi Dench's sharp sounding voice doesn't help matters and further removes me from the experience. It's a bad script and a bad choice for the role. And while my favorite narration is the Jeremy Irons version, i'd still take Walter Cronkite's voice over Judi Dench's. Though again I think Irons was the best narrator out of them all. He absolutely nailed the tone.
I do want to mention that i'm not at all against a female voice as the SSE narrator. I just don't think Judi Dench works. Kate Mulgrew I think would make a really good choice, or perhaps even Gillian Anderson.