A concrete plant was being constructed on vacant land adjacent to his shop. He originally agreed to sell his land, but then backed out. He was angry the concrete plant cut off his shortcut access through their vacant land (he had no easement). So he decided to try to murder anyone who he viewed as standing in his way. It is very lucky that he got stuck before he could fully execute his plan.
"Investigators later found Heemeyer's handwritten list of targets. According to the police, it included the buildings he destroyed, the local Catholic church (which he did not damage), and the names of various people who had sided against him in past disputes."
https://en.wikipedia.org/wiki/Marvin_Heemeyer
"He drove the machine out of his shop through the wall, then plowed through the concrete plant, the Town Hall, a newspaper office, a former judge’s widow’s home, a hardware store, and other homes. Authorities realized that every business or home that had been bulldozed had some connection to Heemeyer and his plight against the zoning committee."
It's akin to something like the Oklahoma City bombing if the terrorists had blown themselves up in the process. But people think it was "cool" that he built his own tank and ignore the rest.
There is no doubt he was wrong but the fact is he built a tank. Can't help but respect his achievement.
I'm going to go ahead and say he was wrong.