This survey is clearly manipulative and designed to get the results they want ("please give us the new shiny design").
The designs are shown at different resolutions: Note how the text on the old one is clearly readable, while the new one is completely unreadable. Additionally, the new design is given a much higher screen. This makes the old design look much more crowded, and obfuscates the fact that you can't fit more than 10 e-mail headers (with truncated subject lines!) onto a 27" screen with the new design. Additionally, they chose a plaintext e-mail with a boring text for the old design screenshot, while using a designed HTML mail for the new design.
The survey itself has one question that is half about usability ("confusing or clear"), with the 4 remaining questions being about bullshitty feel-good/marketing attributes ("boring or inspiring", "unprofessional or professional", "outdated or modern", "untrustworthy or trustworthy") carefully picked to only care about visual appearance.
A much more attractive redesign idea would be showing full threads with sent and received messages in context like Gmail does, while maintaining the standard three-pane view (just allow to scroll up in the bottom pane to see older messages, including sent ones).
Edit to add some things I noticed while writing another response: Note how the "tasks" list is cut off because it simply no longer fits the screen (where the current version has enough space to show it), missing UI elements in the new design (the entire quick filter bar, which would reduce the available space to 3 (!) e-mail headers), the harshly truncated and thus useless subject lines in the new design, the lack of the "this is a draft" toolbar in the new design, that was added to make the old one look more crowded.
Thunderbird is forgetting their target audience. I suspect that people who like shiny over features have long switched to web interfaces. The new design would take away what used to appeal to their remaining users.
It's quite obvious that it's marketing and that the survey is biased towards the new UI design.
Though I'm not sure it has been intently designed like this. Hanlon's razor tells us this probably happened because of incompetence and being clueless. IMHO it reflects the survey authors bias more than a malicious intent.
The designs are shown at different resolutions: Note how the text on the old one is clearly readable, while the new one is completely unreadable. Additionally, the new design is given a much higher screen. This makes the old design look much more crowded, and obfuscates the fact that you can't fit more than 10 e-mail headers (with truncated subject lines!) onto a 27" screen with the new design. Additionally, they chose a plaintext e-mail with a boring text for the old design screenshot, while using a designed HTML mail for the new design.
Here's a slightly fairer mockup: https://i.imgur.com/wTLYTV6.png for direct comparison with https://images.typeform.com/images/7E2EfHaFjYdy/image/defaul... - I've redone the text on the subject of the selected entry to show how it would look like without the blur resulting from scaling the available mockup.
The survey itself has one question that is half about usability ("confusing or clear"), with the 4 remaining questions being about bullshitty feel-good/marketing attributes ("boring or inspiring", "unprofessional or professional", "outdated or modern", "untrustworthy or trustworthy") carefully picked to only care about visual appearance.
A much more attractive redesign idea would be showing full threads with sent and received messages in context like Gmail does, while maintaining the standard three-pane view (just allow to scroll up in the bottom pane to see older messages, including sent ones).
Edit to add some things I noticed while writing another response: Note how the "tasks" list is cut off because it simply no longer fits the screen (where the current version has enough space to show it), missing UI elements in the new design (the entire quick filter bar, which would reduce the available space to 3 (!) e-mail headers), the harshly truncated and thus useless subject lines in the new design, the lack of the "this is a draft" toolbar in the new design, that was added to make the old one look more crowded.
Thunderbird is forgetting their target audience. I suspect that people who like shiny over features have long switched to web interfaces. The new design would take away what used to appeal to their remaining users.