Because they have almost definitely already factored in the loss from people boycotting vs the gain due to killing the resale market into their analysis. They are fully aware that some people are going to refuse to buy digital only

The unfortunate truth is that physical sales have been ever declining so the writing was on the wall

Edit: And you can't really compare the PS2 and PS5 in terms of competition. PS5 isn't just competing against other consoles, it's also competing against netflix, youtube, tiktok, any endless scrolling platform. There were much fewer options for entertainment in 2001 than there are now