This is true in the US as well. And until the 409a rule, it was also exactly how you state. After 409a, private companies are required to speculate at their current value, and this sets the difference between your strike price and that at which you purchased the stock. It's this difference which is taxable. The US was trying to fix something that didn't exactly have a problem, making sure people are being taxed on profits, I think this was misguided.

The unintended consequences are exactly what is spelled out in this article, people with less means cannot exercise stock b/c of two reasons, the cost and then the tax, actually raising the cost on illiquid assets.

This is broken, and causes the type of self imposed entrapment described in the article. If this is a big deal to you, contact you congresspeople and ask them to "fix" or so that the tax is only due on liquidation of the stock.