Driver signing problems are enough to qualify as incompatible. If you have to do workarounds, then that is enough for most people out there who don't have much knowledge of operating systems.
Microsoft has not and will not give up on moving people to their apps. The inclusion of One Drive into the operating system is one example of this. Removing some of the apps built into Windows 10 is difficult (though not impossible with a bit of searching on the net), but shouldn't be necessary. But it is part of the price you pay for the free operating system.
Its all part of a long term strategy to move their customers into a more closed system, like exists for OSX, and Android and iOS. They can never close it off entirely, for their main customers are found in the business world, and they have too many proprietary programs. But pushing their own programs, their own solutions to common computing tasks is just going to accelerate.
And Xercus...TMT is no longer for sale. You won't find it except through "dubious" sources. It seems to work ok in Windows 10, but may eventually cause corruption. This is a difficult thing to determine, but I guarantee you can get the program working in Windows 10, you just might not be able to predict when or if it will cause problems.