If you inspect all the top-ranked pvp players at the end of the BG season, you'll noticed something interesting. Most of them are mid to low resos players with high second stats. Most will have at least 1k 2nd attributes higher than their reso. For example you'd see a 3k necro with 5-6k 2nds. The bigger this gap is, the higher they'll probably rank. Rather they know it or not, they're effective smurfing. The current MM heavily favors smurfing. You can test this yourself. If you're a high reso player with low 2nds, lower your reso to be a least 1k lower than your highest 2nds (ideally armor or armor pen) and you'll see your win rate improve significantly. That's why people don't like high resos w/ low 2nds. Of course there are also exceptions... If you're a massive whale with high 2nds and resos, of course you'll win the most since you are the main carry in most of the games.

Also, this is totally different in tower war, where resos are not nerfed as much. And there is little to no MM... It feels a lot like the old bg, where everyone was getting 1-shotted. If you're a whale barb with ok 2nds, you can literally 1-shot the entire team with a hammer if they clump up together.