I share this observation and concern. I have owned three Bigfoots. The 9.6 camper I ordered new from the factory. I specifically ordered no luggage rack, no ladder, no antenna - no unnecessary roof penetrations. It turned out to be a requirement to have the ladder, since the roof vent was the fire escape. You cannot avoid some things like vents. I did this because my previous Bigfoot 5th wheel had numerous gratuitous roof penetrations. The ones for the awning eventually leaked, rotting some of the paneling and wood stiffeners embedded in the wall. My current camper (BF10.4) I found new (but sitting at a dealer for 4 years). It has an antenna, roof rack, ladder, awning; counting them up there must be 40 or 50 screws through the roof that need not have been there.
Another issue is the quality of the vents. The plumbing vents in particular (but also some of the others) are very pliable plastic. Screwing down the flanges simply squeezes the sealant out of the joint under the screw, bowing the flange. And afterward they flop about so easily there is really no way to seal them long term. The sealing rim of these things needs to be stiff enough to put to pressure on the sealant, otherwise you must use an adhesive sealant and a lot of Faith.
On the fiberglass top of a BF or NL, it is feasible - and not that much work - to simply remove the unnecessary junk from the roof and patch the holes by fiberglassing them over. On the roof, the patches don't have to look good. I've been thinking about doing that at least for my awning, which I never use, and involves at least 20 holes.
