This is sort of a continuation of a discussion we had years ago on here over Gunblade, one which was recently brought up in the AP item changes thread, and I still don't fully agree with your position. So, ultimately we know what your stance on hybrid items is, and I was wondering if you could expand upon that just a little bit for us. The problem you brought up was that in order for hybrid items to be good, a character's kit needed to be watered down in order for that itemization to work for them. But that's a stance I don't completely agree with.
For a long time, hybrid items were so extremely gold efficient it was kind of unreal. That, more than anything else, was the problem in my opinion. When you had all these champions who could benefit from both AP and AD, it only made sense that they had to have lower ratios because the hybrid items were so incredibly gold efficient. To me, that is where the flaw existed in hybrid itemization design. I don't think any special consideration should be given to these items just for being hybrid. The catch should be that they are good only if you can actually use all of the stats on them, but if not then you should be shooting yourself in the foot because the item should not be efficient for those champions.
There's a second factor working against hybrid champions, which is that the late game damage potential does end up dropping off. If you were to build a fully hybrid champion, there would be no efficient way to itemize for penetration because no such items exist with both armor and magic pen. In the mid game, champions are likely to only have itemized armor or magic resist, not both, so in that sense a hybrid champion is likely to be stronger than others. But without penetration, this only lasts for as long as your opponent has only itemized for one defense. In the late game, tanks are likely to have ~130 magic resist and ~180 armor (at least, I always tend to have more armor than MR). At that point, hybrid itemization isn't as useful because you have no way to effectively cut through the resistance of your opponent. Sure, you could pick up Void Staff or Last Whisper/Black Cleaver if you so choose, but these will be of less use to a hybrid champion than they would be to one that has only focused on AD or AP.
Like I said, I would love to hear your thoughts a little bit more in depth on this topic because I don't really buy your argument. If it's purely an opinion-based thing, I could understand it, but I would love to hear your thoughts about it in general.