Nobody needs title insurance BUT
Title insurance simply is insurance that warrants that the title conveyed to you is free of problems. In all the timeshares I have, I never obtain insurance. However, I have a little expertise. Your concern is not that Marriott has good title (they do and they pay attorneys nicely for it). The concern is whether the person you are obtaining title from does. If you trust them, no problem. If you have no idea who the seller is, you could have problems down the road. There are many way to cloud the titles. On the Western Threads I reported the problem San Clemente Inn had. A big California title insurance company had warranted to a seller that the property next door was clear. Actually, the property the seller wanted went right through the SCI driveway. That is the exception and cost the seller nicely.