And really that's what's changed: people don't have to spend as much time searching for more diamonds to repair and replace all their gear. So they don't have to spend lots of time mining if they don't want to.
This is why I like Mending even though I still think it's OP. I never really liked mining and now I don't have to. What I enjoy is building and since I put Mending on all my gear, I haven't used a single diamond. I have about 15 stacks of diamonds so that's likely to last me forever now.
People were moaning about AFK fish farms but I have found trading is an even easier way to get Mending. Yesterday I cured two zombie villagers, one of which was a librarian who offered Mending as a first level trade. Whichever way you get Mending, it's not hard and nerfing farms will make almost no difference.
I still think Mending is OP, but I also still like it, because enchanting is such a screwed up system. If we had more control over enchanting then I might not mind having to make new gear from time to time. With the current system getting "perfect" gear is such a tedious, frustrating, time consuming and difficult task that I feel mending is needed to balance out the mess Mojang made of enchanting.
If we could craft enchants the way we craft other things, then replacing gear would just be part of the routine. You gather the materials you need to craft new armor, then get what you need to craft the enchants. It would actually be challenging, rather than rage inducingly frustrating.
Wasting lapis and XP on trash enchants while trying to get the table to give you something you actually want, only to have bane of arthropods or some other crap enchant tag along. How could anyone have thought that was a good idea? I mean, just think about what we do now, AFK fishing farms, infinite villager breeders, automated farms, trading halls, and it's all to avoid using the enchanting table.
I still think that they should use the old repair system and have Mending replace renaming - in fact, I actually implemented it in my mod, with a few changes to make non-Mending items cheaper than they were in vanilla while Mending items cost about the same; this makes it a bit more of a challenge to make gear that lasts forever (as opposed to just spending 7 levels + the base cost) while still requiring resources and anvils, and being unable to make maxed-out gear that lasts forever (particularly when combined with my mod's custom armor and tools, which can only be repaired with units due to the cost; the fact that you can buy any piece of diamond gear prior to 1.8 devalues diamonds as much as 1.9's Mending does, if not more since you don't even need to mine any to start with).
Along with this, reduce the chances of getting enchanted books from librarians (3 books per librarian, with one trade unlocked from the start, is a bit too much); I think that the more random trading system they had before 1.8 makes things more interesting (you still eventually unlock all of the same items but in completely different orders); back then you only got a single enchantment per librarian and there was only a 1.75% chance per final offer trade to unlock it (maybe a bit too rare, plus I got Mending easier than I should have by exploiting the fact that they can replace enchantments with cheaper ones even as their quality decreases, with a bunch of emeralds as a bonus from trading their last offer (an emerald for a written book) many times).
Related, I also still think the same about enchanting itself (as it was before 1.8; spend 30 levels (or more often, 1 or 22 levels + a book, then you don't need to waste diamond gear; level 22 is enough to give you decent enchantments, including the valuable Unbreaking III (unavailable from the table on weapons and armor in 1.6.4) while not being as expensive as 30) to get totally random enchantments; by comparison, 3 lapis + a bit over a third of the XP to get one known enchantment is nothing) - if you have gear that lasts forever why complain about it being a bit difficult to make the ideal gear? Even with the added challenge of getting Mending for my gear in my last world I took only slightly longer to get to the "end game" (when I actually start using said gear); including time I spent making a couple additional bases and railways later on about 86% of the time I played on the world was spent caving.