Spirit Visage vs. Banshee's Veil

A friend and I were having a really, really long debate over which Spectre's Cowl item is better: or . As a basic reminder, SV is 106% gold efficient, gives 50 less hp, the same magic resist, and the same health regen as BV, plus gives 10% CDR. With its passive, however, it actually gives 20% more health regen than BV plus 20% extra health from all incoming sources (except teammates). BV, on the other hand, is 96.73% gold efficient and will block the first ability used against you. Here's my problem with that: you don't get to choose which ability it is. If it was more like a QSS, then of course it'd be more useful, but as is you don't know what you're going to be hit with. It could literally be wasted on anything. It might be good in bronze or silver, maybe even low gold, but eventually everyone is gonna know to hit you with something before trying to use important spells against you.

For example, let's say you're going after a Syndra. What you need to block is her stun. What you'll most likely block is one of her slows. Admittedly that is one more than you'd block with SV, but she still has another and once you're stunned you're at her mercy. At that point you have to hope you get a heal from somewhere because you're not gonna flash away from her ult. And SV will help you get that much more out of the heal, plus if you have lifesteal you can fight her after she does her combo and is a sitting duck. Another example: Alistar combo, made easier because he can't mess up the timing and punt you away, and he just wanted to knock you up anyway.

Specifically for your front liners, BV's passive is super useless. You're in the front line. You're going to be walking around in front of your squishies getting hit by stuff in between the enemy's farming. You're going to get hit by something unless they have a full melee team in which case it doesn't really matter which of these you build, it should be a win. And when you are in the front line, health regen is an important stat, and SV will give you more of it.

The only real argument I've seen for BV over SV is that pros build it more often. Not the reasoning that pros have, just the fact that they build it. So why is it generally considered the better item (when your champ doesn't rely on incoming health)?