I'm sorry you feel that way and before we delve into the matter deeply I will preface my arguments with I hope you stay on Reddthat but I completely understand your point of view. I also hope that Sync fixes their application to only show downvotes when it is applicable.

Lemmy is Reddit like. We are not reddit. We may have a name that was originally a pun. I wanted to take the best of our previous platform and enjoy our time here.

People's preconceptions around voting is incorrect with any sorting algorithm on Lemmy. Top is the only one that filters by vote counts.
All sorting algorithms use voting as one piece to determine where it should be placed in your "feed". The amount of comments and interactions inside the post are also weighted in the algorithm. So if you are sorting via Hot, someone who comments very recently will actually be at the top of the comment section. This negates the (lack of a better term) "Reddit effect". Where coming in late to a post results in your comment have zero engagement.

There are many reasons people vote and I couldn't even list them all because they are personal reasons which are different for each individual. Agreement, disagreement, disgust, humorous etc. Out of the 4 listed here how many would you vote up? The Reddit answer would be 2. The Lemmy answer (in my view) would be at minimum 3 with disgust being the outlier.
Disagreement should not mean a downvote. You may hate my answer, you may dislike their answer, but that doesn't mean downvote. Disagreements is what makes the world go round. Differing points of views, different experiences, different values.
As long as you can be constructive in your point and you/we remain civil that would be a good conversation. Even if the conversation ends with both of us in disagreement! That is the Reddthat experience I want to foster and the ideal little corner of the internet I want to see happen.

While I understand the annoyances that come with being unable to downvote offtopic posts or downvoting personal attacks etc. Not replying and not engaging in the off topic content will result that comment going all-the-way to the bottom. Thus the same effect is reached.
For all other content such as personal attacks, abusive behaviour, or NSFW content in SFW only communities, you need to use the report button instead, because that type of behaviour should not be allowed in any community.
Reporting also can be utilised for not just comments but for posts that meet any of the conditions you specified.

As with the fediverse and as others have already alluded in reply to this. I'm not locking you here. You are able to signup somewhere else, and with tools like lemmy-migrate you can sync all of your subscriptions and be up and running in little to no time!

Obviously I don't want you to move away and I want you to have the best experience possible but at the same time I cannot see a reason to enable downvotes. Besides from the "feelgood/feel like you are contributing to the community". There are too many "downsides" which I hashed out in your linked post which make me feel uncomfortable to enable the feature at this point in time.

Downvotes, at their core are from another platform which doesn't align with the ideals I have for Reddthat, which is for health communication. When people associate a score they instinctively think it is worth/not worth something.

I hope that answers all your questions on my thought process, decision making, and how downvoting does not contribute to healthy community.

Cheers,
Tiff