I think this is a little too cynical. I've seen elements of what you describe in previous jobs, but never all at the same time, and never to the same extent.
Then again, the culture and the work varies in different cities and in different roles. In London we tend to get excellent developers joining the industry (traditionally there hasn't been much else for good developers locally) so you can typically expect to have skilled colleagues. And the closer you get to the front office, the more money there is for IT projects, and the more remit you have for writing good software.
It's funny you should mention London - our London counterparts always did speak differently of their hours, managers, and opportunity for growth. So I agree with you!
I worked exclusively on front-office systems nearly for the entirety of my time as a developer for an investment bank. I didn't even get into how there are very few opportunities for growth and other, more HR-related/culture aspects of the job.
I'm glad you have good things to say about your work! I just wish I could describe the time that I and my colleagues spent at those banks in a better light. It was utterly life-altering when I left. I felt like I was living for the first time since college.
I think most finance jobs are somewhat better than what he described-- it sounds like he's taken some crappy jobs-- but I don't doubt what he is saying. Code quality issues in finance are well-known and seem to be systemic. Hours are widely variable; there are 9-to-6 IT jobs and there are others that involve more stereotypical (read: awful) finance hours.
I think finance is a great place to work (yes, even as a full-time programmer) if you have a strategic reason for being there (VCs like financial experience, there are some interesting machine learning problems) but I would say that, in general, you're best off if you know you have the social and political skills to get the best work and, if you don't, finance is not likely to treat you well.
Then again, the culture and the work varies in different cities and in different roles. In London we tend to get excellent developers joining the industry (traditionally there hasn't been much else for good developers locally) so you can typically expect to have skilled colleagues. And the closer you get to the front office, the more money there is for IT projects, and the more remit you have for writing good software.