With certain armies being "tough" lists overall, it seems a tad unfair for vanilla Space Marines. Sure, non-vanilla Astartes such as Space Wolves and Blood Angels have extremely powerful units, but standard Marines just fall flat.
And with the upcoming Dark Angels release, who knows just how much more outmatched Marines are going to be.
Let's face it: anti-tank weapons are expensive points-wise. Monstrous creatures are nearly godlike in 6th edition. And standard equipment makes a huge difference.
Take for example Chaos Marines. Yes, many players complained that GW ditched God-specific armies, and their Dreadnought got nerfed. But the first thing that stood out was their standard gear was better than a regular Marine. An extra attack in melee provided by a close combat weapon changes everything. Factor in all the crazy toys they have: monstrous creature Daemon Princes, Greater Daemons, almost all the SM vehicles (Land Raiders, Predators, Vindicators, Rhinos and Razorbacks), Obliterators, and cheaper yet more lethal Terminators. It makes me wonder just how Space Marines are supposed to successfully fight that.
And now, they're getting an updated codex, while regular Space Marines are going to be even further from competitive. This isn't to say that other codexes don't need a boost: Eldar, Tau, Tyranids, and from what I've heard Sisters of Battle was underpowered too.
It's just discouraging when I lay out my relatively formidable army, and I look across the table and see an unbeatable amount of armor, monstrous creatures, or even just overall "better" units despite being Astartes at core.