Well Gang,
I've stated this many, many times on these forums. WE (all who are on and ask or reply to the questions, statements, threads or posts) ONLY read of issues REPORTED on here and a couple of other forums about Winne roof seam issues. In all reality, of all the RVers that roam around the U.S. at any given time, and are Winne and Itasca owners, just how many ACTUALLY have the so-called roof issues?
As has been stated, apparently it's NOT a roof issue to Winnebago 'cause, THEY'RE STILL DOING IT THIS WAY! As for the comment about older folks that have no business climbing on ladders to do any form of inspection or, any maintenance, well, that's an easy one. If they can afford the coach, and cannot do that type of maintenance, then they can afford for a tech to do it for them.
This roof thing is not rocket science. It's a simple design and, some semi-annual checking is all that's needed to make sure things are what it's supposed to be. If one added fasteners, while you MIGHT assist the adhesive/sealant in retaining the roof, you'd also create hundreds of potential leak points, depending on how many screws you'd use.
Scott