Alright, I feel kind of bad for the OP...it seems after all he's gone to a lot of trouble to make his point, and we've all been rather mean to him (except for that one kiss ass troll), so I skimmed his most recent test results....
50 flak vs. 40 cobalts -- 22 flak survive
Let's just first take that at face value...no reinforcements, no cap abilities, no considerations for how likely that fight is to even occur...
Standard credit to resource ratio is 4.5, though I'll go with 4 since this is early game and thus you are more inclined to do some selling....per ship, that puts a garda (375/40/25) at 635 and a cobalt (300/55/0) at 520....
So, garda spammer is spending 31,750 for his 50 flak while cobalt spammer is spending 20,800 for his 40 LFs...now, all the LFs died so that guy lost 20,800 worth of shit...28 flak died, so that dude lost 17,780 worth of shit...
For some perspective, the LF spam lost 17% more in terms of resources...however, the flak person invested 52% more resources...let me say that again: flak fleet cost 52% more than LF fleet, but LF fleet only lost 17% more...
On the basis of cost effectiveness the flak actually did rather poorly...counters aside, I would sure hope the flak would win in this situation considering that the flak fleet had 52% more invested in to it...furthermore, this was a very unfair fight since the "fairness" was determined by fleet supply, a poor comparison in the early game when maintenance is really low and the two limiting factors are resources and construction time, not fleet supply....
A better setup would be a per cost equivalence, in which case you would be pitting only 33 gardas against 40 cobalts, and I challenge the OP to show the gardas winning that battle...
One must also consider the aspect of construction times, which can easily be a limiting factor early game, especially if feed comes into play...per ship (and on faster speed), cobalts take 17s while gardas take 25s...for a 50 garda vs. 40 cobalt setup, the flak fleet took 1250s to build while the LF fleet took 680s to build...for perspective, by the time all 40 LFs are built, the flak fleet would only have 27 ships...
Regardless of whether you go by cost or construction time, the fair fight is 27-33 gardas vs. 40 cobalts, a far cry from the OP's 50 vs. 40 setup...when you equalize with cost or construction time, flak don't really seem all that out of line...again, if the OP can show 33 gardas beating 40 cobalts I might maybe be slightly impressed...maybe...
Now, if you were to do a similar setup, say pit 70 TEC corvettes against 60 javelises (which would cost 53% more), the corvettes would still win provided they were microed properly (I got about half of them to survive)...so, while LFs still do win against flak in fair fights, perhaps you'd still gripe they don't counter them as hard as other early game counters....
But then there is the big kahuna of draw backs for flak: they suck at focus firing...even per fleet supply, they will never compare well to LFs or LRFs when it comes to killing orkies or capital ships, and so even if your flak scrapped a slight win in the fair 33 garda vs. 40 cobalts, they would come at a the disadvantage of being terrible at killing the enemy cap, stopping an Orky rush, or quickly wiping structures...seems like a fair trade: the ship fairs better against it's early counter, but sucks at everything else early game...
Perhaps most importantly, skilled players can elicit the "confused sperm" phenomenon with a few corvettes or with their own LFs (grimm has demonstrated how to do this in great detail, cat has also been a big trainer for noobs in doing this)...in other words, a skilled player can exploit the phenomenon through other means that don't have the huge drawback of shitty focus firing capabilities....
In short, you are still better off spamming LFs than going for flak instead...in small fleet engagements, in battles involving Orkies, and in situations where you have to drive off a cap or kill a frigate factory, the LFs will come out on top...the only situation where flak might be advantageous to spam is if the frontliners are far apart and the first engagement will be with large fleets...well that and when facing a Ragnarov, cause that Ragnarov won't be able to do shit against all those flak circling around it...what a shitty titan...