The poor little guy passed while I was out today

he really didn't look that bad and no other fish is even close to sick or looking poorly in anyway.
I broke down and called my ex for advice..
He tested with his briefcase sized test kit and green lighted the tank.
"I got the huge compliment on my farlowella that they are touchy fish and mine looks stellar

YAY me!!
He agrees to fin rot but stated that "Gourami are sensitive due to the way they are mostly bred, the breeders you will be getting fish from from Pet-smart cheat and dose Antibiotics to reduce losses so you end up getting weak fish"
He offered some "Fish mox" If I wanted to try another and instructions on how to wean em down, but also said I'd be better off using a few of his favorite shops for my fish and staying away from chain stores.
I'm Inclined to believe him but has anyone ever heard this of Gourami? are they really bred weak like that?
Edit: he did go on for a bit about how he was able to pay so many of our bills with the fish he bred in the basement,(he really did.) quote" A good breeder pays attention to viability of the strain, and then his profit"
I have a new perspective of a man I thought I knew, and to think I got pissed when he called off something due to " A tank emergency"
Dont get me wrong, more to the separation than just that but makes me think there is an aspect of him I never bothered to get to know, A good one at that.