Agree with the second part, disagree with the first part. No doubt for a starter its faster to build an average pokemon with EVs and move but if comparing IV breeding and EV training it'll definitely be IV breeding.
1. IV breeding includes inheriting moves where the pokemon can't learn naturally
2. EVs can be changed even at lvl 100 and does affect total stats where IVs cannot be changed once you received the egg unless you hack the game.
3. 4 EV=1 point of stat at lvl 100, 1 IV= 1 point of stat at lvl 100. Maximum reach for IVs = 31x6x4 = equivalent to 744 EV, where EV training cap at 510.
Eventhough IV breeding are time consuming but it's only hard at the beginning. Once you get your first flawless pokemon it can be used in cross breeding with different species but same egg grp to turn your target pokemons into flawless IVs easily.
While learning to IV breed is important at some point, for someone just learning to build "good" pokemon, I definitely feel like EV training is far more important to pick up first. While I see your point about having flawless IVs across the board giving more boosts than EVs overall, that's looking at it in a very advanced way that's not necessary for new comers. Not all pokemon need all of their stats maxed out for example. Having a 31 attack stat on an Alakazam for example is nice to look at, but not really doing much for the pokemon itself.
Similarly, for any given stat, IVs can boost them up to 31 points total where as putting 252 EVs in a stat will boost its value by 63 points. IVs are certainly important, but when you put the boost total like that (Having 31 IVs across the board being equivalent to 744 EVs) you imply that you're similarly evenly distributing the EV spread, 744/6= 124, which would essentially be like giving your pokemon 10 of each of the vitamins then training each stat by a little more. The end result is a pokemon that has EVs something similar to what you get playing through the story line. As bad as that sounds, when I was explaining EV training to my friend a few years ago the first thing he did was go out and give his Aerodactyl as many random vitamins as he could xD it's like noooo you're missing the point.
I do have to agree though that with this generation and with all of the nice tools available (Destiny Knot mechanics, flawless IV pokemon being available every where including dittos in certain friend safaris) IV breeding will take a lot less time to learn and get into this generation. I still stand by my argument that EV training is more important though.