It really feels this way. Honestly, it's just obnoxious that people are willing to change their profile picture about something that they know is wrong, but they won't actually do anything about it or contribute to meaningful movements.

What in principle could they do instead?

This symbolic act of protest and solidarity has caught your attention. I think that's as good a sign as any that it's having the intended effect!

You're partially right about limitations, but there's a deeper logic behind why this actually works - via cultural transmission mechanisms.

The ice bucket challenge raised millions for ALS research despite some or many people doing it for clout. Ribbons helped destigmatize amd raise awareness for aids, which bolstered funding support. Their purpose was to effect social change thru awareness and solidarity.

There aren't many accessible ways for individuals to push back against cases of corporate overreach. Lois isn't claiming profile pictures fix everything but rather aiming to build a network of people who wish to push back on cases of corp overreach - a strategic initiative.

Discussions and debates like this, are part of how cultural change starts. Small symbolic acts that get people talking & thinking about issues they might otherwise not consider.

He did make a "sequel" addressing that: https://youtube.com/watch?v=SkL9vzW7nY0

You usually can't do much against anti-repair or anti-consumer stuff alone (especially in organizations), and that people often feel like they're the only ones who care in a five mile radius. The idea is that the clippy pics activate people to actually do something, because they feel like that precondition of others also caring and wanting to do something is fulfilled.