Companies don't really care about rules per se. They care about their risk appetite, and whether the consequences of their actions create risk above that appetite level.

The simple calculus is: will it cost me more to comply, or more to ignore? If a company chooses the more costly option, they are betraying their shareholders and being managed poorly.

If you do not fine early and often, you are almost mandating that companies ignore the legislation. If this continues for several years, then you almost make it impossible to turn around later and fine, as businesses will want to know what's changed now. You will create an impression of uncertainty and instability, which is the last thing businesses want, and the last thing you want to do to encourage investment.

If you just set and enforce the rules from the start, then everyone can relax, do the right thing and be happy about it. It's funny how rarely this actually seems to happen.