Would you sell shovels to other people if the shovels mined gold on their own? The real reason that the ASIC companies take preorders is to pay for the high up

Would you sell shovels to other people if the shovels mined gold on their own? The real reason that the ASIC companies take preorders is to pay for the high upfront engineering costs. Additionally, a single entity controlling a majority of the bitcoin network would decrease confidence in Bitcoin, so it is in everyones best interest to spread out the mining devices.