Turned out he had 3 nails in tires. 1 in the front, 2 in the back.
That's one reason right there. You can have a foreign object in the tire causing more damage (by not taking it out) and not know about it.
However, the main reason I'll never use it again is because of what that crap did to my rim:
The Good, the Bad, and the Ugly.
On the first point, your right, whether you have goop in your tires or not, you SHOULD be checking them. But the point being, he didn't suffer 'catastrophic' failure from a blow out. Who knows how long the tires were punctured like that?
Hum, I'm thinking the damage may have been caused by Ride On (it was Ride On wasn't it?). But it looks to me like its secondary to damage caused from a previous tire install. Looks like the machine gave that inside bead area a good gouging and what were seeing is the affects of oxidation of that damage. I don't believe it was caused by the Ride On. The rest of the rim is 'clean'.
All that being said, Ride On sits in the tread area of the tire. It doesn't 'coat' the entire inside of the tire so as to cause damage like that. Actually, now that I think about it, the damage could have just been easily caused by water vapour from unfiltered compressed air.
Me, I'll be more than happy to pay some tire monkey an extra 10 to wash out any shit I have have put in, but judging from my past experience, the rims are spotless when the tires removed.
Not quiet NEPTR territory, but theirs a lot of evidence that sealants can save your ass, while theirs just a bit of circumstantial evidence that they cause harm.