On several occasions, Mullenweg has publicly challenged competitors to WordPress and WordPress.com. He has stated that he prefers to settle disputes in the
court of public opinion and described his approach as "
brinksmanship", noting that the potential cost of legal action could put Automattic in a "tough spot". In 2008, shortly before WordPress 2.5's release,
Six Apart's
Movable Type published "A WordPress 2.5 Upgrade Guide"—a comparison of their
CMS with their rival, WordPress—as a company blog article that Mullenweg characterized as "desperate and dirty". In 2013, developers on the digital marketplace Envato were banned from speaking at WordPress events after he criticized the platform for selling WordPress themes with the graphics and CSS components under a proprietary license instead of the
GPL. In 2016, Mullenweg accused
Wix.com, a competitor to WordPress.com, of reusing WordPress's mobile text editor code in Wix's own mobile app without adhering to the terms of the GPL. Despite the license's requirement to publish anything built with GPL code under the GPL, Wix's CEO claimed that the company open-sourced their forked version of the component and satisfied the license's terms before the app switched to its own fork of the
MIT-licensed text editor that the WordPress editor was based upon. The new fork added a clause to the MIT license that forbids redistribution under any other license. In 2022, Mullenweg criticized
GoDaddy for not reinvesting in the WordPress project sufficiently. On January 9, 2025, the representative of the WordPress Sustainability team, Thijs Buijs, resigned via WordPress.org’s
Slack channel, citing dissatisfaction with Matt Mullenweg’s December 24, 2024, Reddit post titled “What drama should I create in 2025?” highlighting concerns about what he described as “unsustainable leadership”. In response, Matt Mullenweg thanked Thijs Buijs for reminding him of the existence of a sustainability team, announced its disbanding, and subsequently closed Wordpress.org's #sustainability Slack channel. During that time, Mullenweg engaged in a public feud with a
transgender Tumblr user who, frustrated with the failure of Tumblr (owned by Automattic) to address
transphobic harassment, posted that she wished Mullenweg would die in a comedic way. The user was subsequently banned. Responding to user uproar, Mullenweg addressed the ban in posts on his personal Tumblr blog, in which he characterized the post as a
death threat, and shared private account information about the user. Mullenweg also responded to individual commenters on Tumblr in posts and
direct messages, and went to
Twitter to respond to the banned user's tweets about the situation. A few days later, transgender employees of Tumblr and Automattic made a post on the official Tumblr staff blog characterizing his response as "unwarranted and harmful" and stating that he did not speak on their behalf. They also said that the user's post was not a realistic threat of violence and not the reason for her ban.
WP Engine dispute == Audrey Capital ==