A couple of things to note:
Bruno Mars wrote an album full of catchy songs designed to make people dance and have fun.
Its not a rap album. Its not aimed at the rap crowd. Its aimed at the masses but with a specific focus on the R&B crowd who are sick of their tastes always being conflated with or taking a backseat to rap. Not everyone wants to hear a sequenced loop for 3 minutes and 30 seconds with no real instruments.
Just because the current generation has grown up devoid of musical arrangements doesn't mean they don't exist. And rapping will never replace singing...EVER.
Because the hip-hop community has co-opted itself into R&B the past few years, it believes it owns the genre. That's partially due to producers like Timbo who was producing hip-hop and R&B artists and blending the sounds and the racist industry itself demanding that every singer have a guest rapper on their song or it won't be a hit. The genres got conflated. Bruno's current records are derivative but nostalgic. People like him because it reminds them of when music was fun...and musical. R&B got weak and rap took it over but Bruno is just a reminder that R&B doesn't have to be resigned to slow jams like it has been seemingly for the past few years. Now, maybe brothas will git off their asses and start playing instruments and singing again. Don't like Bruno? Do better.
Secondly, 4:44 was not really all that consumable for people outside of pure hip-hop fans. Sorry. That's just the truth. It was made for people who "listen to the lyrics rather than the music". Its arrogant to believe that nobody else understands Jay-Z. FOH with that. People just didn't like it as much. Real talk. I sometimes think the only reason that Kendrick is doing so well is because he has so many industry co-signers. I'm not shitting on either of them as they both had good records but The Grammys have always been about the industry, not the masses like the Billboard awards and the Mtv music awards. The industry was feelin' Bruno because he made some fun music in a time where the social climate to be politically correct has made everyone tense. People don't want to be tense; they want to loosen up.
Thirdly,
I could have really done without that PSA bullshit from Janelle Monae. I hate to see her go that route because people liked her because she was cute and fun and energetic. She's gonna alienate her audience with the feminism speeches. Feminism seems to turn every cute chick frumpy or less attractive. Its revenge of the ugly broads. They will never get male attention, so they sway cute chicks to their cause and frump them down so they aren't cute anymore. Well played, feminazis.