i dunno bout you but......

[Mooncatt]

I still find secondary batteries totally useless. they might hit once in a blue moon if your lucky.

I spoke to my dad whos a navy vet. he said a DD wouldn't get within 15km of a BB in a million years( he served on two DDS). DDs were supposed to take out CLs, subs and maybe CAs at a push if there was more than one DD. the small calibre guns were meant for self defense only and the torps they carried were again used for cruisers. (my dad served in the royal navy in the mid to late 60s to the mid 70s so probably the tech back then was a whole lot different to the 1940s)

in this game DDs deem it appropriate to close on BBs without (so it seems) too much retribution. the secondaries don't seem to be able to hit the broadside of a barn door and I know this issue has supposed to have been patched but it doesn't seem to have made too much of a difference. personally I would like to see DDs have a more direct role in this game. in real life they were NOT BB killers. they were more anti sub and CL.

[Shaftoe]

Because secondaries are pretty much useless. Need need higher damage and accuracy in order to be effective - at least against destroyers. Right now, it's better to invest money and tonnage into something other than secondaries. 

[Skeksis]

This is an old battle between historians and gameplay.

But we have to wait until the campaign release to see how viable units and there components really are, to see if historical components does equal historical fleets, cause if not then gameplay will have to be balance, like secondaries buff.

But until then.

[Shaftoe]

Gameplay sets limitations, such as number of shells and limited time to destroy enemies. Therefore, rigorous historicity is an obstruction in the way of enjoyable gameplay. Wise players who want to win realize they must abide by gameplay requirements, therefore secondary guns fall out of favor, and historicity dies - since there's no point in using weapons, which very essence realism advocates try to protect. 

[Alcar]

Perhaps I am in the minority, but I do find my secondaries useful against smaller vessels. I love putting the big guns on a primary target and the secondaries on a destroyer. Usually they take care of business.

That said, I do find a destroyer much scarier to my capital ships than a battle ship in most missions, so that indicates a problem...

[Galis]

Same, that's why I never bother with any guns smaller than 152mm. Though I usually try to never go below 203mm on secondaries. 
And when I want to sink a destroyer I usually point all my guns at her, including main artillery. Because usually it's the main artillery that sinks it. 

[Norbert Sattler]

102 and 127 can work well in the early periods but the smallest two are useless even against torpedo boats and transport ships.

[Steeltrap]

The "historically accurate" value of secondary guns in WW2 at least was as DP heavy AA when coupled with high angle fire control systems, potential shore bombardment use, and CLOSE defence. Oh, and for raiders to use to sink transports v main gun ammo.

We can count out AA for a very long time at least, and we don't know much about opportunities for shore bombardment when it comes to capturing territory in the campaign.

That leaves us with what constitutes "close", and just how effective would that 'defence' be.

Grossly inflating the hit rates of everything has highlighted other shortcomings, as it must inevitably.

Either ships seem ludicrously durable as the soak up hit after hit after hit (because of the inflated hit rates) OR they sink too easily/rapidly, again because they take far more hits in a 10 minute period than was ever likely to be the case.

Plus, yes, 8" secondary guns are better than 6" in just about every respect, but that is in no small part due to the game currently, in my opinion at least, significantly underplaying the added difficulties of putting more and more larger and larger weapon systems on a ship. There are reasons we didn't see IRL the sorts of things we see in the game frequently. The fact the game rewards us for designing things we know simply weren't efficient or effective IRL also highlights issues.

Thus it really comes down to expectations and game mechanics. Do people want 5-6" secondary guns in the 1920s to wreck DDs at 10km? Do they want those same guns to be able to hurt their BBs effectively from similar ranges? I for one am rather sick of seeing my towers getting increasingly trashed by popguns with grossly inflated hit rates, but maybe that puts me in a minority.