I like your idea because of the following reason:
Bitcointalk will get another "problem" in a few years: inactive users on DT (1 or 2) whose feedback was (and is) still very valuable for the community but sometimes for single cases not accurate anymore because issues are solved or accounts are getting hacked etc.. If an account on DT is inactive and some feedbacks are getting inaccurate we have to decide: leave them on DT including all inaccurate feedbacks or remove
all of his feedbacks by removing them from DT completely. Both variants aren't a good solution in my opinion.
An example: Zepher's negative rating left on sportsbet.io's account:
Multiple scam accusations against this casino in the scam section. The reference linked shows them withholding 21.5 BTC, of which 15 BTC was a deposit with 6.5 BTC winnings. Sportsbet have not paid out the 21.5 BTC, nor even returned the original deposit of 15 BTC. I would advise against playing at this casino until all allegations are fully resolved. AFAIK the scam accusations are resolved:
Sportsbet.io has been resolved the accusation about 15 BTC which was mentioned by @Zepher & @Lutpin negative feedback's. So ignore both negative feedback's about that accusation and read reference link for better understand. Zepher is no more ( Hope he is in Haven) and Lutpin is very inactive, so feedback's couldn't delete or edit right now. I am bothering to leave this feedback since people's raising questions about resolved issue. https://bitcointalk.org/index.php?action=trust;u=832366I think the outcome is a litte bit confusing for all readers and sportsbet.io has (to be accurate two) outdated ratings which are not relevant anymore. To keep such valuable users on DT while ensuring the inaccurate ones can be removed, OP's suggestion is a good idea.
That's only one case where a feedback isn't accurate anymore and I'm 100% sure that will happen much more often when Bitcointalk gets older. So at least for such cases I like OP's suggestion.
Perhaps requiring maybe 5 DT members to agree with a down vote before confirming it would be a good idea.
5 DTs agree & click down vote ensures potentially harsh or unfair neg is not shown by default.
+1
Limits for downvoted vs. upvoted feedbacks should be high to prevent abuse.