Frankly, Marcus does not sound like he is very computer Saavy. He sounds like one of these people who knows how to write some PHP scripts, but does not really understand the details of what goes on behind it - so assumes that what this guy is doing is some terribly complicated hack.
I think the argentine guy probably searched the website for vulnerabilities as a way to get business. He found one and contacted Marcus. Marcus then freaked out and panicked, leading to this.
POF is hardly a great example of superior software engineering. The whole point of POF is really affiliate lead generation for other off-network dating sites.
ASP.net is just Visual Basic. It's not the most complicated language to learn, and you don't need to know much about computers to develop in ASP or VB.
Saying 'ASP.NET is VB' is sort of like saying "General Motors is a Buick Skylark." It just doesn't make any sense. ASP.NET is a framework for developing web applications. You can use any number of supported languages - C#, VB.NET, J#, Ruby, Python, F#, etc. I can only assume that he conflated the late 90s scripting combo of ASP/VBscript with ASP.NET.
It's obviously possible to write terrible code in any language, with the aid of any framework. It sounds like POF did just that.
The original site was in ASP, then he migrated it to ASP.net. I doubt that he paid any attention to the 'framework' part of things. He just did a VB syntax migration.
Rails is just Ruby. It's not the most complicated language to learn, and you don't need to know much about computers to START developing in ruby or Rails.
See? This has nothing to do with platforms, and everything to do with realizing your strengths and weaknesses, and improving your platform when hundreds, thousands, or even millions of users trust you with their data. You can't just chalk this up to POF being on a platform you think is somehow inferior to your platform of choice.
I think the argentine guy probably searched the website for vulnerabilities as a way to get business. He found one and contacted Marcus. Marcus then freaked out and panicked, leading to this.