That's because they ARE too good to be true....
Can you substantiate your claim?
OP, do you have a link to an article detailing what is being considered?
Here is a hypothetical scenario based on a Federal spending:
According to this information:
https://www.fin.gc.ca/tax-impot/2014/html-eng.asp
Canada spends about 26% of its tax dollars on transfer to persons through social programs and another 13% on other transfer payments that are also related to social assistance (more specifically aboriginals and learning programs).
In the best case scenario, a system that eliminates most social programs but gives everyone over 19 a guaranteed income would save 39% of the tax expenditures. That represents 108 billion dollars.
Considering that the demographic of people over 19 years of age represents about 75 percent of the Canadian population (33,476,000 as of 2011). This means that 25,700,000 people would be eligible for the program.
Meaning that a cost neutral program would provide everyone with 4,200$ per person per year and still keep the free healthcare.
You might say that this is not enough to live on and you would be right. But I see it as a proof in concept. In a progressive tax system, the amount could potentially be increased to 20,000$ per year and most of it would be clawed back through taxes at higher income levels.
Also consider that most provinces also spent a lot of money on social assistance (14 billion dollars for Ontario in 2011).