It's common for folks in finance to have undergrad technical degrees (e.g., physics, math, CS) and graduate degrees in something more closely related to finance such as an MBA or MS in quantitative finance. (Although the pure quants will usually have a PhD in math or physics.)
But frankly if you're a technical person IMO finance is a ghetto: once you're in, it's hard to get out. In no other industry can you make as much money to do work that generally speaking is substantially behind the curve technically (e.g., pre-STL C++ is the standard development language and mindset, and most of the time you're just moving stuff to and from CSV files and databases). But if you're disciplined with your spending it's a great way to save seed capital if one day you want to jump ship and try a startup.
I strongly disagree, as to HN's "conventional opinion". I think most participants and probably most lurkers, would say that finance is probably, on average, a more lucrative field, but a CS degree from a no-name university would probably be better for getting into finance, the field, than an equivalent finance degree. This assumes you're working for someone else.
A finance degree is less useful for a technology/coding business/startup than a CS one. This is the raison d'etre of the forum. I would also contend that for getting FY$, personally financially independent rich, a startup is probably at minimum equivalent to working in finance. As such, neither is a bad choice, but the CS degree has better options.