If you throw enough money on FPGAs, or GPUs and electricity, today, you can also try to attack the network (if that's your main concern),
it has always been possible with enough resources/enough money to spend, the thing is, that if you have that much resources/money, it's more profitable to be an "honest miner" than to attack the network (which doesn't make you any profit at all).
at the beginning i said anyone wanna make a 50% attack will pay huge money and get nothing, that's also what u r talking about.
but manufacture of ASIC has enough source but no need to pay anything.
because all machines just in his hand before shipping
can u imagine the mint join in the market directly?
who can supervise and control the manufacture of ASIC?
NONE!
ok, maybe u can say "i trust that guy" or all miner trust this guy.
then back to my first point
BTC sys not base on the trust on
any human but math and logic.
even all miners and developers trust someone is not enough.