Support theatre provides the appearance of supporting customers when in fact it is just treating customers poorly based on a management system that disrespects customers. It is a similar idea to security theatre that has become so popular for government in the USA for the last 10 years.
Companies that practices support theatre are usually very focused on cutting the company's cost and not "wasting" the companies time fixing the problems they create for customers or even helping customers put on "band-aids" to cope with the injuries the company has inflicted on the customer. Those companies also don't learn from their failures to improve and stop future customers from suffering the consequences of their poor processes.
It is painful to interact with such companies.