I don't quite buy that. Sure they may be getting better or tighter at getting the melodies, and certainly working harder for them, placing that as the goal, but I don't think it's something that's been missing from them at all, I just think it's a different belief in their music and how it's structured. To go back to Rattle & Hum, look at All I Want Is You. A U2 melodic pop single if there ever was one. Forget the sound and production, the length and build etc, and that could fit easily onto The Bomb as far as 'quality of melody' goes. What about With or Without You? There are also plenty, dozens, of other U2 songs that have a great, great melody there, but for whatever reason, it's been avoided or stripped - and the songs are better for it.
What if With or Without You had been written and recorded circa 2004? A build up that takes that long and starts that quiet? No way. We'd be banging the strings and big full strength chorus straight after the first couple of lines as per Miracle Drug and Original of the Species. But no, instead there's patience and calm and no need to blow the load early. The melody is there, it's how it's used. The ending isn't given away at the beginning. The beauty in that song is specificaly that it doesn't go for bigness at any point. If God Will Send His Angels - another example, but slightly different. If they'd wanted that to be the big pop single, all it takes is a different structure and sound. No change in melody, just take away the beauty and build and hit us up from the start. You can slightly here that in the crappola way they edited it for the single. Anyway, point is, amazing melodies have always been there. It's not their existence or lack of that is different, it's all in the sound and structure. They haven't worked them the same way because they had a different feel for the songs in the past. I personally think Miracle Drug would be infinetely better if they'd kept it low and relatively calm right up until the guitar explosion and the last chorus, but that's not what they do now. They're not giving you a taste here and there waiting for you to be absolutely drooling then giving it to you near the end, briefly, before fading away again, leaving you salivating for more. There is no U2 song that is rushing to please as quickly as Original of the Species. The structure is the key there, and what they are doing (on some, but not all songs) is milking the melody for every drop it's got right from the get go. Whether you like that or not is personal opinion, and mine is that, like food as I said above, the melody, the beauty of the song, is the flavour in the food. Subtle hints throughout the meal are perfect. What they are asking you to do on some songs is what all pop songs do. It's not the icing on the cake, it's just eating a bucket of the icing. You eat the cake and get those little bits of chocolate icing and you love it and want more, more, more, but if you just mixed up a load of the icing, you'll be the happiest person in the world for a little while, but within a few spoonfulls you'd be well over the flavour very quickly. I'm not sure if I'm wording that analogy correctly, but I'm sure you know what I mean.... But each to their own. I love a song like If God Will Send or Velvet Dress or Who's Gonna Ride or With or Without You or Running to Stand Still etc etc for the way they have within them outstanding melodies, but take their time to open up, give you a little, push you back, pull you in, never give themselves right up to you. I don't like a song like Original of the Species because it's all laid out there in front of you from the get go, the first listen, the first taste it's all there. It makes the experience fleeting. I've eaten too much of it by the third listen. I slept with it on the first date. What have these songs got left to give? Personal opinion, but thats where it is with me. Melodies, whatever. U2 have always had them. The difference is in their use and delivery and they've over cooked it by a mile in my view.
unless he's an actor like in Electrical Storm... 
In reality, if anything is boring and repititive, it's forum members like you. You've lost your sparkle.
