Is nobody from the beta left?
Alright, if you think the Vasari are so poor now in a stand up fight, in beta, they were even poorer in such a fight. I don't remember exact numbers, but the Vasari cost for cost (both in terms of resource cost and fleet upkeep cost) were the worst of all the races, by far, which the beta community cried out against. So the devs buffed it. At the time, yes, I thought the Vasari needed a buff, but they are fine now, because I never pit a Vasari fleet against an evenly matched, much less superior force, I have the TEC for that. The Vasari are a decimated empire on the run, the devs never designed them to be good in a standup fight. Vasari are all about guerilla warfare. TEC were designed with a standup fight in mind. It's not about combat prowess, it's about strategy. The devs straight out said that the Vasari's advanced technology (lore wise) was not focused in a combat area.
And as far as racial balancing, I would imagine the other races would give an arm and a leg for the abillity to ignore phase lanes and warp their ships directly from one of their planets to an enemy planet (Kostura Cannon, and that Marauder that you say has such poor DPS). Personally, if I could play as TEC, I would imagine I would pay twice the cost of the Marauder to have one with no DPS at all, just so I could race it to the enemy's homeworld and jump my fleet in.
This is not Starcraft, the Vasari are not protoss. This is not Halo, the Vasari are not Covenant. I could keep going, but I hope I've made my point.
Sorry if it sounded condescending or rude, it was not intended to be.