The ML in lemmy.ml (and also lemmygrad.ml) stands for Marxism–Leninism, of whom supporters of this political philosophy were the majority of Lemmy users until reddit started to migrate here a week ago. The founder and lead developer of Lemmy is a supporter of this philosophy, and many people are avoiding Lemmy because of it.

However, in my view it's not a reason not to use Lemmy. Lemmy is Open Source, and uses a protocol common across other projects (such as Mastodon, a federated twitter-like platform - you can actually subscribe to Lemmy communities from Mastodon, though I believe the reverse doesn't yet work). Because of this, many other developers with all sorts of political views have joined in development, and even if the core development team takes Lemmy in a direction that the community doesn't want, the code is open source so a group of developers can fork (copy) the code and build it in the direction they want. And the two different versions can talk to each other because everything is running on the same protocol.