Some plants are definitely not good to have around. Here, ragwort is a legally controlled weed as, if cattle eat it, it kills them and dairy farming is a massive part of the economy. It also grows fast like...a weed.
My garden. which was hugely overgrown when we moved in, is riddled with ivy which chokes everything else to death and what I think Americans call nutweed (I'm not sure of the UK nomenclature) which also grows voraciously. I have been waging a major battle against both for the past year and I think I may be winning.