Lemmy is still small and it doesn't have the crowd sourced discussion or reach that Reddit does.

Sure some people might be after the karma or attention, but it's bad to just lump everyone together with that assumption. People have different reasons for continuing to use other platforms, and it's not productive to throw around insults. I assume lots of Reddit users are aware of the issues, but continue to use it for other reasons. Some people may be using Lemmy / fediverse on top of Reddit.

• People may read content relevant to them to get discussion that doesn't exist on Lemmy yet. That might include social causes, career pages, hobbies, etc.

• People might post on Reddit to reach more people. When it comes to social causes / movements, reaching people is important wherever those people might be. I extend this to other platforms too. As annoying as it might feel, a lot of regular users are primarily on Instagram, TikTok, etc. and it's worth the effort to get the message to those people. Lots of people learn about social causes that way

For what it's worth, you can't get people to move to the Fediverse if they don't learn about it