Actually, it is more that people learned via experience it isn’t nearly as necessary, or great when playing with randies. It still kicks butt just as well as it always has, but the issue is that the Sharpshooter especially has access to far better options than the Boltgun with the combination of the Lasgun + Power Sword which gives the Veteran much higher killing potential than the Boltgun ever did against greater range of foes.
The weaknesses of the Boltgun become evident when you realise that suppression is a major negative, and having 15 shots to take out 10+ shooters before they can wipe the floor with you isn’t exactly a viable option. It is also a redundant option to use with the Power Sword around as they both offer you the same advantages you would have against hordes and armoured elites. You are far better off using the Lasgun against everything that isn’t heavily armoured and the Power Sword to fill the gap against those and hordes.
Adorable, but no. I would very much like to see you clear an entire room of shooters by yourself as the Zealot using the Boltgun. Note, let’s make the room the Data Interrogation section in the repair mission. You will most likely kill probably 2, maybe 3 of the shooters before you are suppressed to high heaven and then blocked from dashing as the first gunner appears around the corner and opens up, killing the Zealot on the spot within a handful of seconds.
In that situation, as the Veteran I just pop Focus Fire to ignore it and then tap everyone once with the Lasgun. In case I get rushed in by horde and/or Ragers/Maulers, I pull out the Power Sword, swing 6 times and continue the mission without a hitch.
But not at once. You can be short range CC with the Surge Staff, a worse Flamer with the Purgator, or long range AoE with the Voidstrike. You will, once again, have a flaw to deal with as the Psyker. If you bring out the Surge Staff, Snipers and Reapers can still easily shred you as they are far out of your reach. Purgator doesn’t have the reach of the Flamer, nor the staggering effect, making it honestly the worst staff in the game in my eyes, and the Voidstrike lacks damage in higher levels. Also, it isn’t the Plasma Gun, it is more closer to the Boltgun for it pens bodies but doesn’t actually damage that much. Again, the Veteran can fight against hordes with 'nades and the Power Sword better than the Psyker in all instances while also being able to take out most elites from max range and the rest while in Melee, and still have plenty of time to fight off the shooters.
Ogryn can either be a really good blocker for your team, or you can be a decent horde clearer, CC guy with the ability to stunlock most elites in the game, but you are also the biggest, easiest target to shoot apart with dedicated fire.
Again, note this recurring theme. Each one of the classes you described doing all-rounding can’t do ALL things with one build. They must specialise somewhat and then give away something in return. The Veteran can.
I need to emphasise something very critical here to you. You have said it yourself, you are bad at melee, so how in the world can you ever, under any circumstances, be able to see how the weapon is as powerful as it is? In your use that thing might not appear to be good because you don’t actually use it on regular basis, but the average joe can shred with the thing way beyond their paygrade.
Again, I don’t have this “squishy in melee” problem when I play my Veteran because nothing can ever hit me since I know how to dodge and also know how to aim the thing to make it one-tap swarmers. No other weapon I have used, from Thunder Hammer to the Eviscerator to the Force Weapon, have EVER come even close to the level of performance I can do with that weapon, and I have all classes levelled up to 30.
Yes, but note something very interesting here, something you might have skipped over. Out of the three weapons you mentioned, 1 is dedicated to the Ranged Class of the game, but also happens to be the single best melee weapon in the game as of right now, while the other two are for THE Melee class in the game. Funny how that happens, huh?