Actually nothing new here, this was the same in the pre-cloud era where everyone in enterprises prefer big names(ibm, microsoft, oracle, ecc) to pass the responsibility to them in case of failures ... aka "nobody get fired because of buying IBM"
but somehow that is never a problem.
When everyone is suffering because AWS is having its bi-yearly 8 hour outage, the CTO isn't blamed, bonus all round, and maybe the AWS sales team takes him for an apology lunch
When the CTO is up for 1500 days straight then has a 2 hour downtime when nobody else does, the CTO is blamed, no bonus, and more likely to get fired
IBM is older, and it's incredibly well documented how mainframes are more expensive to run than normal servers.