I don't think anybody is disagreeing that composers should charge a rate that values their time and skills. But if you aren't able to be rate-flexible depending on the client/project, aren't you going to be missing out on a lot of gigs? This doesn't matter so much if you have a day job (because you won't go broke), but if music is your day job, you need those jobs to survive.
So many musicians/composers will take to the internet complaining how overworked and underpaid they are, and how they never find any good producers who actually value their work. They want to try and "fix" the music industry so people will just magically start paying them more money. Meanwhile there are people taking advantage of all of the opportunities being left open by the people who are unwilling to reduce their rates and/or make other negotiations (royalties, publishing rights, etc.). There will always be someone who is willing to work harder for less money than you.
Let's say you somehow calculate out your rate to be $500/min. That's the quote you put on your website, and the quote you tell everyone who calls you. You get a call from a podcast host looking for an intro theme, and a AAA studio who wants a main theme (each 1 minute long). Would you not adjust your rates accordingly? If not, you're probably not going to get the podcast gig, and you're going to get ripped off on the AAA theme.
Also, if nobody wants to pay you $500/min for your music, is your music really worth $500/min?
I can agree on that, for sure. Stay away from those assholes!