The old saying "spoiling the ship for an apath of tar" comes to mind.
But this isn't a joke for you poor sods who have shell'd out thousands on a new caravan. Fortunately warrantee's cover the event.
As a process technician and engineer, it never suprises me that manufacturers turn a blind eye to a production fault rather than "bastardise" (jargon for make a bulletproof plan) the process. That's mainly down to the fact that they would then have to do a product recall which has a detramental affect on future sales. You see, nobody remembers the good things that happen but if you make a mistake, it takes years to win back confidence. Just think about the "leaky lunar" jibe back in the 70's and 80's or the best one was Jerald Rattner who famously branded one of his own products "total crap" while on television.
I had to repair the shower tray in my Abbey Freestyle 18 months ago. It was not covered by a warrantee, so I had to do a DIY fix as a new shower tray was both too expensive and too difficult to fit while still living in the van.
I had to cut the rim of the tray away from the toilet plinth to avoid a total strip down of the rear of the caravan. Having got the tray out, I could see the cause of the two 200mm long splits in the ridges of the tray floor. The high density foam pad had collapsed and didn't support the floor profile. I glassfibre'd the splits and an area 100mm around them to add strength. then I bonded the foam pad with silicon sealant to the tray base. Because all the work was hidden on the underside of the tray you have to get on your knee's to see the fine crack line. It was a big job that took 3 days to do, but was worthwhile in the end because it is still 100% fixed todate, and considering we are full timing, that is a lot of use after repair. I would guess that I have done a 10 year repair based on general touring use.
My philosophy is that if it's broke, you haven't got anything to loose by having a go to fix it, but a whole lot of knowledge to learn and a heap of money saved in your pocket.
I fixed mine for £15 of glassfibre kit from halfords and 6 tubes of everbuild 336 mastic that I had lying around. Compare that to £128 for a new tray and about £200 to fit and you'll see what i mean.