Reducing the number of heat sinks is unfair to explorers. I don't care how you try to sugar-coat it. It just is.
We lose out because a minority of PvP-people are crying about the latest meta build. And I bet there are a lot more people using HSL's to minimize damage from close encounters with stars then there people using them for combat.
At the least I hope FD reduce the mass of an HSL to compensate for the lower ammo' count. It's only fair that explorers get some kind of recompense.
It punishing explorers is a bit overly dramatic. Explorers are heading out into the unknown so should take extra care not to crash into stats. As mentioned in the thread moaning about this it is very rare you come up against such scenarios where you NEED to drop a heat sink.
The other option would be not to take a ship that runs and gains heat really quickly when exploring. I used a DBX and only need the heat sink once.