It seems to me that a lot of the developers have never seen real users use commercial software on a day to day basis and I don't even mean real power-users. The customer service manager at my work breezes through Excel, Outlook, and Dynamics Nav while on the phone with a customer to give them estimates on product lead-times and changes the sales orders on the fly. She uses tons of shortcuts and keyboard shortcuts in all the apps but in no way would be considered a geek or techie. She's a user who has been doing this for a long time and while she doesn't care about DB2, she is glad to have a toolbar that can refresh external data in an Excel sheet with a single click. It makes her life easy and enables her to take orders worth tens of thousands of dolalrs daily. Commercial software exist not to win design or elegance awards but to increase productivity. Also they tend to support integration with Active Directory/LDAP, Terminal Server, Office, Outlook, and tons of Microsoft apps that makes my life as an IT admin really easy and thus productive.
Honestly, I think us developers/designers have it wrong when it comes to UI. We think there is only one kind of right interface and it must be a clean-cut page with a big green call-to-action button that says "Sign Up". Anything other than this is a mess and confuses users. Maybe this is true for webpages visited by grandmas but I think in typical business environment, it's quite the contrary. Users are accustomed to words and icons and expect them to work in a similar way in every application. So if there is a Print icon in Firefox or Excel, it must do only one thing and that is print the current document. However, while we developers think that the 100 other icons in the same window confuse the user, I've noticed that users don't even notice the icons they don't immediately recognize. What does that mean? It means Office and such feature-rich apps aren't mess but rather have a lot more functional icons that users recognize and can immediately access. The extra icons i.e. the feature-bloat is invisible to the user.
Also his point about not having to be bullied by management makes no difference to anyone other than him. The users and junior developers are still at the whim and mercy of someone who says "no" based on their own personal opinion, no matter how technically correct it might be. I'm not saying commercial software is superior to OSS or vice versa. I'm just saying I find it hard to believe that OSS is getting better while closed-source software is getting worse based on these arguments.