Well......let's look at the answers to your question.
-Those who don't have one, wouldn't own one.
-Those who have them, like them. Oh yeah, the industry is making millions of them....must be a bigger issue than we thought!
-Those who bought coaches where the manufacturer went cheap and tried to use Schwintek slides on something that they shouldn't, didn't work.
My favorite.....are the engineers explaining the math. The only thing they neglect to mention is that the stress is on the chassis, not the roof line. If the RV had a second floor, yes, the opening could be an issue. Show me someone on here who's opening collpased under normal use.