The El Primero movement used in Daytonas back in 90s and early 00s is a reliable and fantastic movement, that is still marketable even after 42 years in history. Rolex actually detuned this movement from 36K Hz to 28.8K as they didn't feel it was necessary to operate the chronograph to 1/10 of a second, but doing so actually increased the power reserve from ~50 to over 70 hrs. IMHO this was one of the few where an outsourced movement didn't make the watch any less sought after.
I think the popularity of Rolex aside from the popular bling factor is they hold their value in general better than most other brands except for a few collectible models. That makes it a "wiser" purchase, should the purchaser decides to sell if afterwards.