Straws become the focus because people like them and find them useful and make them a part of their culture and then proposed bans threaten to take them away. People do focus on them, I’ve seen plenty of online arguments about straw bans and the ethics of straws, which happens because they are a part of the lives of the people arguing about them, unlike fishing nets which they never use or see.

There is a side of environmentalism that comes off as being smugly superior about your lifestyle and disparaging and seeking to shame and control in small ways (usually poorer) people who don’t live that way, with the pretext that it’s about saving the planet. To me that sort of thing seems like it’s mainly just a dumpster fire of political capital, purely counterproductive.