I am all for lower taxes - perhaps using the money saved to lower personal income tax. I just dont think we should socialize people's investment decisions. I do not want a culture that people to invest to make a loss to minimize their tax liability. It distorts the market, and goes against the free market principal of conservative economic.
For example, no one in their right mind would invest 500K into a business that generate loss each year (and no one would pay more to buy it off you a year later). They are doing that now, because, they would suffer the loss now, and make a larger capital gain later on. I am not against savy investors for doing this, but I am against, subsidizing their losses now, and then give them a bigger capital gains tax concession in the future when they do make a profit. To me, its just double dipping.
This also creates an environment of property speculation. Where the investors invest not for its principal to income ratio, but rather speculation of future gains. This opens up a big problem down the road, when eventually, property prices have to readjust.
Now, you mention about shares. Say you have a next door neighbor, he earns the same as you are. But he wanted to get rich quick, and put 100k into a small obscure prospecting company. But it went sour, and he lost half of it. Now, this means, in order to make the short fall on the revenue, the government need to raise more money from you. How would you feel about it?
I see all taxes paid by me as my money until I reconcile at the end of the year, and whatever I can't claw back is 'gone' money, but what is is mine is mine.
You may see it as all taxes paid as the governments money and tax write offs / returns as dubious accounting practice design to rip off the government.
I begrudge every cent taken from me, as a vast majority of that money is p1ssed away on failed and imprudent ventures.