Devs can't list out everything explicitly; there is something in the EULA about missuse of game mechanics. Also, getting a little more NIC back on insurance than the cost of a bot + insurance is not a game breaker in and of itself.
The exploit itself is not even fully exploitable to the majority of the population, and it wasn't until it was fully and truely exploited on an industrial scale that it became an issue the devs needed to deal with.
When it got to the point it needed to be stopped, they had no choice but to penalize everyone that had even a small profit from the exploit to make it fair, even though only major corporations could fully exploit.
Players buying bots off the market and insuring them and losing them in PVP may have made enough NIC back to buy and insure another bot + a few thousand extra, but lost NIC overall because of the module costs.
Corps with large scale mining, dedicated industrial characters, and EP in insurance could quickly convert bots to cash without waiting to sell on the market. This isn't even a matter of the insurance payout being played versus the current cost of the bots. It was just more expiedient to build and scrap bots than it was to sell them.
There was SO MUCH ore and SO LITTLE pvp that there was just no market for the volume of bots that dedicated players could produce; something like 36 Mechs every 3 days per dedicated industrialist alt.
It was wrong and against the spirit of the game to build'n-bash but it still points back to the game itself
1) having too much and too easy resources
2) not enough reason to pvp and lose bots the right way
3) crafting designed to support massive pvp, again without the pvp
CS didn't have the production capacity or resources to mine and build or even buy and build so didn't have anything to do with this, but if we had, we probably would have also. I can totally see why a CEO sitting on the NIC and resouces to produce 100's of bots a day wouldn't just want to 'waste' time by not making them.
I really really have to point the finger back at the game here, and by extensions the devs. I don't think Infestation gave a sh*t about the NIC. If there was any reason in the game for blowing up more bots legitimately, they would have done so.
Also, build'n-bash is not the same exploit as manipulating the insurance payout so you could buy bots straight off the market and blow them up for profit. If there is insurance, and you build bots using gathered resources, you're always going to make a profit. The question is if you would make MORE NIC selling the bot or selling the ORE then in making a bot; which you may if the market could stand it, but its INSTANT NIC with the insurance...
of course after while you get enough NIC, and bored of gathering, so you just buy the ore and switch to Buy'n-bash. This is where its a real exploit, because you are doing very little work for the profit.
Once Buy'n-bash became prevalent, insurance became totally broken and we get the dev post.
I and my corp didn't do this, but I find the 'high-horse' attitude of some players just truely miss the mark in the "spin the wheel of blame" game.
Lets hope that not only the players that let their greed run away, but also the devs, take away from this that the game needs attention; and keeping your loyal players informed of what is going on in the grand scheme is invaluable.