Cost to make ships = the reason suicide fleets won't happen.
For a pilot on a ship, you got to expect certain gear to go along, like G-Force dumpening suits, which would be destroyed when tose pilots die. Which increases the cost.
Suicide Fleets are like burning money for nothing. And on top of that, they can be blown to bits before they can even get to you or... you know, wait for them to get on an intercept and hit them with all the EMP weaponry you have, fry them, board the ship, kill the pilot, steal the ship and scrap it to sell for money.
The counterplay is there, people just have to put effort on using their brains.