i definitely agree with you about the value and benefit of reblogging, which is exactly why we added viewing tags in the notes view as an official feature (it's still fairly new!). i get it, and i agree. we already have rolled out new tour guides for new users that point out reblogging as an essential part of the tumblr experience. we're working to promote more reblogs in recommendations so people see them more often. we added a new feed of popular reblogs as a tab on the dashboard. there's more to come to help promote reblogs, as we've always done.
but the "imbalance" is a myth. i can literally look at the overall data of tumblr's reblog and like usage across the entire platform over time and i can't see any change in the likes-to-reblogs ratio. i double-checked as soon as i saw these rumors start flying around for my own sanity! if there was a systemic problem here, i'd be worried, and would've answered the above ask much differently.
sure, you can point out a handful of examples where there's a ratio you don't normally see, but tumblr has millions of posts and reblogs every day. people have always used the Like button significantly more than the Reblog button. there are always outliers, and they do not reflect the norm. that's just how big tumblr is!
and it just hurts seeing people on tumblr, who obviously love tumblr and are passionate about it, try to police how other people use the platform in this way. if someone wants to use likes more than reblogs, i think that's perfectly fine. i'm happy seeing people find things they like. i wish this same energy went into trying to get other people to sign up for tumblr and make it a home and help us grow as a community, instead of making new users feel bad about the way they're choosing to use the platform. that just encourages them to leave, and that's not sustainable.
we have always had recommendation systems on tumblr, for over a decade, like any social media platform, and they are powered by a myriad of signals. likes and reblogs are two of those signals. we can't keep the site running without those signals. you can definitely disable a lot of "the algorithm" on tumblr for yourself, but a lot of people on tumblr every day actually enjoy it and rely on it. they are not using tumblr "wrong", they're just not using it the same way you are. there's no imbalance there, as far as i'm concerned.