I've trotted out this analogy from time to time, so sorry for repeating myself, but to me, following H!P occupies a place in my mind similar to that of following a home sports team. I feel naturally loyal to them and to the idea of maintaining an ongoing interest in them, even if it waxes and wanes periodically. I wish for their success and hope their new members flourish.
I reject the idea that some ex-fans have that everyone is meant to "outgrow" H!P fandom and there's maybe something wrong with people who still have an interest.
People don't normally say to Dallas residents, "Why are you so obsessed with those men running around in tight outfits? The only possible reason is that you must be some kind of perv!" Or "What's wrong with you that you're still following the Cowboys? They haven't won a championship in 25 years, find a new hobby!" Just like every Dallasite, I'm gonna keep hoping for a big win forever, no matter how distant the last world championship was. But even without that win, I'm still on H!P's side.
To your other questions, back when Kaori graduated, for like 5 seconds I thought that might be it for me, but I soon realized that it's not about just one person. For every girl who leaves, others just as good or better come into their own. I feel that the level of talent, beauty, and even the music quality is as strong now as it was back in the golden or platinum eras. Certainly overall singing ability is way better now in my opinion. And I like that H!P mostly dropped the occasionally oversexed fanservice aspect on one hand, and the nursery school H!P egg concept on the other (and the combination of both
) and has become a generally wholesome talent showcase for young women with very few of the creepy wota aspects that some other agencies promote.
The only things I really miss are the scripted humor bits like Haromoni, and their frequent interactions on comedy programs. But that is made up for by more regular in-house content than we could've ever dreamed about 20 years ago. Plus the ability to follow the careers of OGs of whom there are more and more every year. Speaking of OGs and things I miss: Eri, goddamit.