I agree with all the points people argue relating to "ain't nobody got time for that".
Back in university, I used to hatch dozens of eggs waiting to get that perfect IVs + nature. It took forever. Yes, they made it easier for parents to pass on IVs, etc., but there wasn't a perfect way to engineer it. Back in university, I had time.
Now I am an adult and I don't have time for that. I love playing through Pokémon and legitimately enjoying the game. But, when it comes to competitive battling, and you want to make multiple teams with multiple builds of the same Pokémon for variations in techniques, IVs + natures + abilities take forever. I don't even have any sort of issue with EVs/levelling - they're *incredibly* easy to do these days - but the other stuff is painfully time consuming. Those people who say IVs don't matter are wrong - in a game of min/max %s, those little numbers make ALL the difference (especially relating to Speed).
In our local tournament, we all GTS our 'mons, all legal builds, we all have a grand old time, and the best man wins.
The day I stop hacking my Pokémon is the day Game Freak give me a timesaving, 100% guaranteed way to engineer my Pokémon's IVs, abilities and natures. I don't care if it's some 100 hour in, post-game, complete your Pokédex sort of function - it just NEEDS to be there for those people who already invest time into the game.