The reason "no one gets fired for buying IBM" is because big players (IBM, Microsoft, Google, Amazon, etc) are known quantities (so you don't need to answer questions around "why would you choose that fly-by-night company, you must have some financial interest!") and critically, if something goes wrong they're big enough to sue.
If you pick a small company and something goes wrong, they might go out of business and leave you with nothing. If they stay in business, you might try to sue them but the company isn't worth enough to make a lawsuit worthwhile. IBM, Microsoft, Amazon, Google, Apple, etc, they're big enough to sue. Which is kind of an insurance policy against something going wrong in the contract.
Nobody ever got fired for buying IBM