"no sights at all"
I'd have to agree to some extent, with the change in the phrase to, "many of my rifles don't have iron sights at all." Further, I have pulled the iron sights off several of my sporters that came so equipped. On top of that, on some of my rifles that retain their iron sights but have a 'scope mounted, I have no easy means afield to pull the scope if it went sour.
I have a lot of time, I hunt a lot, close to home. If a scope goes bad, I can mark it off to bad luck, go home and get another rifle (or maybe back to the truck), and get to hunt again, soon, maybe even that same AM/PM. Not everybody is that fortunate. If I were limited to a short, couple of week(end) season at deer camp, and had to drive a couple of hours to get there, I would rethink things. Likewise, if I had a bunch of cash sunk in a guided hunt off somewhere, I would have iron sights, and a means to remove a bad scope, and spare scopes, pre sighted with rings, in camp, even a second rifle at camp if it were plausible. But I don't have to in my circumstances.
I have not had a "decent" scope in my collection fail. By decent, I mean a scope from one of the big names in about the $200 dollar range +/- and up. I have had a number of lesser priced scopes, mostly on .22's, come unglued. I have a Mini30 and a Ruger .44 semi carbine that have beat cheaper scopes to pieces in pretty short order. Those carbines, and all but one of my .22's, now have better scopes and have not given further problems. But stuff happens.....however my experience is a decent scope these days is a pretty reliable item.
I still encounter see-thru mounts on rifles in the woods and clubs, usually holding economy scopes. My Dad was a fan, but I doubt Dad ever spent more than $100 bucks on a scope, so he had failures, and hunted in the era when 'scopes were more prone to failure as well. I agree they place the head to high off the comb in most instances, make the rifle clunky, and are prone to knocks and blows due to their higher profile, not conducive to long life on a budget scope. I think they compromise trajectory a bit too, though not enough to effect a lot of woods distance shooting.
I've posted before that a set of Leupold QRL rings I have return to a useful zero, but they are as ugly as all get out, and prone to snag stuff as well. I have a couple of rifles that I have taped a hex/torx key under the ammo butt cuff, very secure, that would allow me to pull the 'scope and use the factory iron sights in the event of a failure. On those rifles, both equipped with peep sights, I can still run the metal sights well enough to hit game if that was the course I wanted to take (and not call it quits and bail for another rifle).