I think you havent seen good hunters, unholy DK and fire mages...
got those 3 in my group and I can tell you that unless blizz nerf the DK and the mages, it is unlikely they nerf DH.
Before comparing your aoe and single target in a time where everyone gear is different etc, you might want to cool down and wait for raids.
in groups there can be as much as 30 ilvl difference in gear... not 3 or 10, 30!
Not sure about a nerf... It's only the beginning of the expansion, raids and mythic + is not even open yet, and we've got a really, like really terrible scalling, vers is our SECOND best stat and crit is only a thing for ST.
What I'd do if I was in charge would be:
1 - make fel rush generate 25 fury passively and change fel mastery into a single target kind of talent, something like "fel rush deals extra damage to the first target stuck" or "something happens if fel rush only hits one target": this way we would have blind fury for aoe damage, fel mastery for single target and chaos cleave for... cleave.
2 - nerf bloodled to only deal 100% of the damage dealt by throw glaive, BUT make it have a chance to crit and also have it's damage scale from vers: we would have some better scalling from crit and vers.
3 - nerf the damage of all skills by 1~10% and make chaos blades a root skill: We would have some better scalling from mastery and haste.
4 - eye beam no longer has a guaranteed crit chance, but it has some effect on crit hits(like extra crit damage): So crit would become a thing for aoe too.
PS: As a unholy dk your friend should not be far behind you and should even be able to surpass you once the gear goes up.
It's the setting that you are in. Dungeon trash is all burst AoE, which the DH excels at quite nicely. On proper single target/mixed mob fights, there are other classes that can and should be beating DHs (assuming same gear/skill level). My friend is an Outlaw Rogue, and despite him being almost 10 ilevels below me, he is slowly creeping up on me in single target. Once he is at my ilevel, I have no doubt he will be beating me.
Don't worry about numbers unless your chosen spec is waaaaaaay ahead of everybody else-- and Havoc isn't. Numbers change every patch, and sometimes in hotfixes, and there's nothing you can do about that. You should be concerned about gameplay-- do you enjoy the mechanics of playing the spec? That's ultimately what matters.
This was my mentality for all of WoD. I played DK all xpac, and it was a bit of a wild ride spec wise. Leveled as Unholy, did 2H Frost in Normal HM, switched back to Unholy for Heroic HM and all of BRF prog, went to DW Frost for Normal and Heroic HFC, switched back to Unholy halfway into Heroic and for Mythic. Death Knights were never chart toppers, with the exception of the first few days of 6.2(? - HFC release). Despite that, I always enjoyed playing the class, and never had the urge to switch.
When DHs came out, I had no desire to really play them, other than to try it out. When they hit, I was immediately hooked. The high movement, fast paced style of the class appeals to me greatly. I've truly found a new main.
I think thats the thing ~ if you're always chasing a damage meter, no class is ever going to feel like home to you. If you enjoy the play style, keep playing. Your friend sounds bitter AF, btw
I'm going to say this as politely as I can...but he needs to learn how to UH DK better.
They can go toe to toe with DH on packs assuming they use their CD's...if they don't and we do (I'm talking EB and FotI here not Meta) we will blow them (and everyone minus a well played monk) out of the water IMHO.
Arms is garbage aoe for 5 man content. Arms depend on 2 long cooldowns to do aoe dmg and if they are not available you do dog shit aoe dmg and in 5 man environment where you pull pack after pack having long cooldowns will not work at all unless you multi pack pull loads of mobs but you cant really do that in mythics effectively all the time at the moment and on mythic + it is definitely not an option so arms being better aoe then demon hunter is just silly to say.
take it from guy who done all mythics 5 mans so far with many different classes and specs and I found best aoe dps for 5 man content is:
Havoc DH
fire mage
WW Monk
our Fire mages with good gear can do close to 2 mil of dmg on aoe packs alone its crazy. It feels like those 3 classes are just not tuned correctly when it comes to aoe as the margin with other classes is just way to big.
Bitch I've been waiting over 10 years for this moment, can't take mah DH away from me
WW Monks do a lot more AoE than I do as a vengeance tank using all my AoE CD's. So I wouldn't really worry about it. What I can see potentially being nerfed is their self healing.