That really depends on what you're doing. In your experience, commodity hardware is the right call.
Building a Public Safety Radio dispatch system? Maybe the SuperMicro isn't the right box for the job. Motorola vs ______? Who's going to ship ten engineers to your doorstep when something goes wrong and lives are literally on the line?
Layers 8 & 9 of the OSI model: Religion & Politics.
Some shops have to buy certain brands because their buddy on the Board of Directors sells that brand, too. Heh. Or it's a large customer. Stupid, but it is life in IT.
I'll give you one guess why the above conversation didn't include Cisco as an option. And it starts with AT & ends with T.
Big companies get into bed with other big companies, right or wrong, they do it. I've been fortunate enough to see both worlds, commodity hardware cranking out piles of cash, and name brand hardware cranking out piles of cash but only because if you stopped using it you'd lose your sweetheart deal with the customer who wants you to use the name brand junk.
Engineers can ride in the back of the bus when the CxOs golfing buddy sells brand X and the Engineers want Brand Y. Or the CxO sees his bonus disappearing into a higher than expected capital cost for Brand Y.
Enjoy being private while you can. Public companies waste incredible amounts of money on stupid crap that lowers their bottom line. I'll just toss the wrong-headed ideas about what Sarbanes-Oxley requires out there as one solid example. SOX compliance audits are about one half a step higher than "utterly retarded" at most companies, because they listen to consultants who get paid by the hour to implement it.