“Simply put, it’s because Bradford pear trees are an invasive species. According to the United States Department of Agriculture, invasive species are any introduced organism that is non-native to a particular ecosystem and can cause harm to the economy, environment, or humans.”
1) non-native (or alien) to the ecosystem under consideration and,
2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health.
God in his eternal wisdom and providence has provided us, through his creation, examples of why “Invasive Species” must be first avoided and secondly, eradicated with extreme prejudice.
Simply put, it is against the natural order and threatens the native species existence.