My guess is it boils down to this para :
… although open source has demonstrated its worth, particularly on servers, the cost of adapting and extending it, for example in writing printer and scanner drivers, and of training, have proved greater than anticipated. The extent to which the potential savings trumpeted in 2007 have proved realisable has, according to the government, been limited – though it declines to give any actual figures. Users have, it claims, also complained of missing functionality, a lack of usability and poor interoperability.
Any new person to the Office likely has already been trained in the products of the proprietary operating system, but not in Linux. They need to be retrained. The new persons are likely discontent having to learn this, and they likely stir up discontentment in the other users who were not happy with the forced move to Linux. These users likely bring with them stories of applications they used in their previous jobs that don’t have similar Linux counterparts. I know a weakness in Linux apps that I think would cause the biggest annoyance in our office if there was a move to Linux is that there is no Linux app that can compete with the functionality of Adobe Acrobat Pro, nor an app that has the user friendly combination of Microsoft-Access. Yes there are Linux apps that can do some functionality in pdf files, but they pale in comparison to Acrobat Pro. The same is true wrt user friendly use of Access. I suspect there are other office specific applications where the proprietary operating system has a lead over Linux as well.
Reference interoperability - it is true wrt office documents produced by Word, Excel, Access, and PowerPoint. In all cases I can point to cases where documents produced by those apps do NOT convert/display well in Linux Open Office / Office Libre. I confess thou, I struggle to understand just who they need to be interoperable with ? My experience with governments is they tell us the citizens the formats we must use/submit, and it is up to us to be interoperable with them. That point was a bit of a surprise.
Maybe they mean interoperable with their home PCs and their hopefully not pirated versions of MS-Office ?
What they state about drivers is likely true in that one just can’t buy any piece of hardware and use it on Linux. This restricts managers with discretionary budgets and that likely annoys them. There are a lot of neat technical items on the market, which do serve some limited purpose related to the office, where there may be no to limited Linux drivers (but no problems obtaining drivers for the proprietary operating system). The same is true for many printers, where there are some printers with drivers for the proprietary operating system, but not for Linux.
wrt proprietary drivers, its common knowledge that ATI and nVidia Linux video graphic drivers are NOT as capable as the MS-Windows proprietary video drivers. Although typically that is only important in playing back movies or playing video games which presumably are not functions for a government office.
Its a bit disappointing to read of this planned change back.