Firstly, I don't live in UK, Canada or Germany so they are irrelevant and aren't worthy of a mention.
"You can't reduce your tax payable by making deductions unrelated to any other income stream (e.g personal expenses deducted from business income) so why allow losses made investing in property against say employment income?"
You need to check your facts!
Simply because it is your overall income that is taxed!
One tax return!
Buying a house to negative gear is not a business income it's a personal income so it affects my personal income and tax liability.
