I'd say it's more the general nature of Microsoft in this particular case. "There should be three different ways to do that" has been the case since Windows 3.1.
Actually, adding LINQ to C# did not introduce any new functionality at all. Everything you can do in LINQ you could already accomplish in C# without LINQ. Yes, I suppose someone could say that the older code was uglier, but it already had the same capabilities as LINQ.
That's been the case for the majority of supposed "new features" in C# for at least the past 8 years or so -- LINQ, inline variables, anonymous functions, string literals etc. It's all just syntactic sugar on top of existing features.
Regex validation cannot verify that an email address is functioning any more than it can verify that a phone number is functioning. But if an address or a number passes formatting checks, one can indeed consider that data "validated". That's what that term means in the business software development industry. We're verifying if the data entered COULD be correct, not double-checking that it IS correct.
You are correct to say that those emails may still bounce, and the phone calls may also not go through. We completely understand that. For this reason, in very specific situations (like registering a new user), we do take that extra step to make sure the communication channel actually works. But there are plenty of situations where that makes absolutely no sense, and/or adds very little value for the cost. Knowing the difference between these two very different use cases certainly does not indicate that these people "don't actually care" about the accuracy of their data.
The article you link to addresses just the one use case where you are registering a new user. Email addresses in business applications are just as often NOT the address of your user. Sales contacts, managers, points of contact, customer support addresses, etc. -- none of these should ever be validated by sending an e-mail. So you still need to validate the hard way in plenty of scenarios.
At least in the US, that results in the dangerous people you mentioned being confined with lots of people with undiagnosed or untreated mental problems and lots of nonviolent (non-dangerous) offenders. On top of that, you have a significant number of innocent people incarcerated also, people who got screwed by the system along the way.
When we place all those people together, in a setting where violent assaults are shockingly common -- and, in particular, the constant threat of rape -- we are definitely making you less safe, not more safe. One might argue that at least the "dangerous people" are preying on other "criminals" while they are inside, but how many of those victims end up becoming MORE dangerous to you and your family due to years of state-supervised abuse?