[Note 7 Questions & Answers] br0adband:
You asked for some views so here are mine, much to the chagrin of many I'm sure but that's ok, that's just fine, really. ;)

Based on currently available information which includes how Li-Ion batteries actually work, I personally would say the actual reason(s) that the Note 7 devices are considered to be defective is not because of the battery itself. So, while having a removable battery is a great thing - and I prefer devices that have removable batteries personally and only buy such devices with my own cash (I got my GS7A as a trade for a laptop so it didn't cost me any cash out of pocket).

Try this hypothetical situation for just a moment, if you will.

Without naming name brands or particular models, say you have a smartphone that has a removable back cover and a removable battery inside. To get to that battery and remove it you must handle the device well enough to be able to get at the back cover, probably find the tiny little gap that most have so you can insert a fingernail into it or perhaps a nail file, a butter knife, anything at all that can fit in that little gap so you can then start to lift the back cover off the device, unsnapping the retainer clips as you do so.

Follow me so far?

After the back cover is fully removed from the device you then have to remove the actual battery itself. Most removable batteries have a spot where you can "hook" a fingernail into and then pull gently to pry the battery up and out of the frame of the phone itself. If necessary you can probably turn the smartphone display side up and then smack the phone into your palm and the battery would probably drop out into hand, but generally most people just use their fingernail or perhaps a spudger to pry the battery loose from the device.

Voila, you've removed the battery entirely, congratulations.

Now here's where it gets interesting:

Say this smartphone has a defect that is occurring at random times on some devices - some of them will exhibit the defect (as cause and effect) and some devices may never exhibit it because of the random nature of how it presents itself. Considering this random nature of the defect presenting itself, say that at some point either while you are actually using your smartphone in your hand, or it's in your pocket, or it's mounted to your dash in your car with a holder, or it's sitting on a desk or table, or anywhere at all really and...

It starts smoking.

I mean it literally starts smoking and the smoke is quiet visible and you can see it easily. You can even smell it as it's happening. If the phone is in your hand when it starts smoking your most common reaction will be to drop the device right then and there, especially if in addition to the smoke you feel some heat buildup, like it was somewhat cool a few seconds ago but now it's smoking and it's getting damned hot, fast.

Again, most people in that situation are going to drop the device immediately.

But your device has a removable battery under the removable back cover, right? So...

If you dropped the device because it was smoking and getting hot there's a chance, a small chance but a chance nonetheless, that in the act of dropping your device when it hits the ground or it lands on a desktop or table top it might just cause the back cover to pop off and the battery might just pop out of the device entirely. That's a possible thing, right, you can actually imagine that dropping a smartphone with a removable back cover and removable battery might just make the back cover pop off and the battery pop out.

Still following me? Good but here's my point.

If you have a smartphone and it starts smoking, anywhere - be it in your hand, pocket, dash holder, tripod holder for pictures, on a flat surface, in a pool, under water, in a toilet, desktop, table, gravel, dirt, sand, on a road, it doesn't matter - the primary way to get the battery out of that device means you have to remove the back cover and then remove the battery and that requires you to hold it but since it's smoking and getting hotter by the second that's not really an option anymore.

So what then? Does that mean having a removable battery is a bad thing? Well, no, not really, but in a situation where the device fails in some manner and causes - that's the important thing here, the cause - the battery to fail as well and burn itself up it means you could potentially suffer some injury yourself because you have to manually remove the back cover then the battery.

tl;dr Yes it's a good thing to have a removable battery, but if a device with a removable battery fails and you want to remove the battery during the failure hoping to save the device itself from further damage, you might be injured yourself because you have to handle the device to some degree to get that failing battery out before it does damage the device or in the most extreme situation explode which destroys the device and also might release the gases from the battery which are incredibly toxic to humans.