I suspect you are not used to reading laws. The age of the law makes no difference.
The only amendment is to give the minister the power to create GUIDANCE.
There is no legal obligation on landowners to control ragwort.

You are clearly wrong on this. Just stop and think for a moment. If you are wrong on this you were told something wrong by someone. Just like all the other false publicity. Read that website again and read the myths section.( i'll bet a lot of money that you only read two pages of the site) I'll bet you thought a lot of the myths were true. All of them have scientific references provided and there is a second site that says the same things.

Ragwort - Common myths

People are being misled by propaganda.