[robertlagrant]

I think the accusations can be divided into several categories:

- actual rent-seeking (as you say, not really true for companies such as Microsoft and Google, except where you see e.g. government documents needing to be submitted in Word. But that's very likely incompetence on behalf of the bureaucracy rather than Microsoft)

- having a dominant market position due to having a very high quality product, or set of products that work together well

- a random grudge phrased as rent-seeking, because the Twitter user in question doesn't know what rent-seeking is, but has seen their friends accuse companies of it

I don't know what the proportions are, but I suspect the former is minimal to nonexistent for e.g. Google.