The site has become stale, and in my opinion, I have found discussions more predictable and interactions less cool.

Why would locking users' discussions (comments) into bubbles of those users they already follow address this? Wouldn't one expect it to make discussion more stale by introducing miniature echo chambers?

I actually like the sharing aspect of Hubski - when I submit a post or click the wheely thing to share a post, I feel I'm curating something for others, and that it's my responsibility to share only what's worth their time. Those others, and that responsibility, feel real to me because they have actively chosen to follow me based on the quality of my past posts and shares. So I had better keep the quality up. I have to suspect this sense of responsibility contributes to the higher quality of both posts and debate on Hubski than on reddit.

So both moves to me sound like a shift in an undesirable direction. Restricting comment visibility will cause echo chambers, while basing feeds on tags will remove that element of responsibility not to waste the time of users who have chosen to follow you.

Please be careful - Hubski is the only general-purpose site I can think of where debate remains intelligent and polite after 10 years. To the users this is worth more than another site with a large userbase, and more than a torrent of mediocre content.