Why wouldn't all investors just sell their deferred preferred before maturity?

The only problem with the security is they are extremely illiquid. As such, it is very difficult to sell them before maturity and receive a reasonable price for the sale. as such, investors generally will have to ride out the investment to maturity. The comment regarding compounded growth is in reference to holding the investment within an RRSP - the money earned can then be reinvested without having to pay tax because the rrsp is a tax deferred plan. As such, the investment can compound tax-free over time until money is ultimately withdrawn. Atmaturity, the income is treated as interest income by the federal government and does not qualify as a dividend.