Neither you nor I know their intent here, we can only make assumptions. For either of us to start believing our assumptions are fact would be sheer hubris.
Looking at some of what they've done in the past two generations, I believe (but cannot be certain) that their intent may be to make competitive battling more accessible to "normal" players, so that PvP is more based on skill than on the ability and free time to grind. Allowing IV's and EV's to be more easily manipulated (without the need for long tedious breeding and training) would go a long way towards that. Sure, the "normal" players would still need help, and it probably wouldn't be in the manual, but hey, that's what sells strategy guides.
Now what you've raised here, and what I disagree with, is the idea that this would create homogeneity. Well, sure, in a poorly designed system it might, but there's plenty of ways it can be done to discourage that. For instance, just like Pokémon can only have 510 total EV's, a change to the IV system to allow for them to be more readily changed and focused may only allow a specific total of IV's. That won't prevent min/maxing, but it does prevent "flawless" Pokémon. If done properly, min/maxing might then lead to greater variety in Pokémon used, as you'd get a much greater variation in the final possible stats for each Pokémon, and subsequently a greater variety in how they end up being used.