Interestingly… or perhaps tellingly… it wasn't until 5th edition the whole marines are all melee centric came about.
Marines have always been shooting, I mean come on, the holy weapon of the Emperor's wrath used to get much more use. (Back when almost every enemy was T3… vs. T5) Once the melee edition (5th) came around, and the meta shifted to super-squads with butt-tons of power weapons attacking at high initiative with multiple, effective ranged weapons did the idea of marines prefering to lay waste to the Emperor's foes with the holy bolter fall out of favour. I mean come on, you want a unit that can only put out 2 shots the enemy gets saves, or a unit shooting 4 shots + charging in with 4 melee attacks each which doesn't allow saves all in the same turn (very slight exageration for dramatic effect)?
I won't even go very far into the current "destroy all established background for a buck" edition (very similar to 5th but now with "wizard did it" buffs and no counter I-win buttons [coughmindshacklecough])… But in the heyday, and according to Codex instruction marines do indeed prefer shooting. Yes, even the Blood Angels (who are actually at the core a codex chapter).
As for your question, I can agree many of the specialities seem slanted to melee. You cannot blame some of them though. A Chaplain should have a crozius as a sign of office, though the chaplain speciality has little in the way of melee talents. The same goes for the Captain speciality, the sword is just a sign of station. Unfortunately most of the advanced specialities seem to have a melee weapon as a "sign of station". It is a little overused. Take a look at the deathwatch veteran specialty, if memory serves it gives many bonuses which can be tailored to ranged fighting. Most of its special abilities are "experience" related, and a lot of the options in the advance tables is centered around getting good gear, though not specifically limited to melee gear.