The author ignored one of the most interesting parts of the Quora post, the patent that Apple filed about a manufacturing process that casts ceramic parts and silicon/rubber parts at the same time to make a single object that has both hard ceramic structure and soft rubber. That would let them unify parts like gaskets and bits that hold other bits into one single process.

So maybe even if the ceramic part of the process takes longer, they might be able to make up for lost time but cutting out steps that are further down the assembly process. To quote the patent:

"As one specific example, ceramic materials have numerous qualities that make them particularly useful for use in electronic device housings. For example, they may be highly scratch resistant, making them particularly well suited for electronic devices that are frequently subject to bumps, scrapes, and scratches, such as wearable electronic devices (e.g., smart watches, glasses and the like), mechanical watches, and other consumer products (including, but not limited to, media players, mobile computers, tablet computing devices, and so on). As a specific example, the high hardness and optical clarity of sapphire crystal (a crystalline ceramic material) may be very well suited as the cover glass for a touch-screen of a wearable electronic device. Ceramic materials may also be relatively light, making handheld or wearable electronic devices easier to carry, wear, and use. Moreover, ceramic materials may be able to achieve a high degree of surface polish making them particularly aesthetically pleasing.

However, ceramic materials typically are more difficult to form into complex geometries than plastics, and, thus, manufacturing housing components from ceramic materials can be more difficult than for other materials. Accordingly, described herein are housing components where a polymer material is co-molded with a ceramic component to form a housing component that includes ceramic and polymer material portions. (As used herein, the terms "polymer" and/or "polymer material" encompass natural and synthetic polymers, plastics, rubbers, and the like.) For example, a ceramic housing portion may be co-molded with a polymer material to form a polymer clip that is directly coupled to the ceramic material and can be used to retain the ceramic component with another housing component. As another example, a polymer material may be co-molded with a ceramic component to form a plastic coating on a portion of the ceramic component

As described herein, a polymer material forming a polymer feature may be coupled to a ceramic component by a co-molding process whereby the polymer material is molded against the ceramic component. By co-molding the polymer material directly onto the ceramic component, the polymer feature may be bonded to the ceramic material without the use of an intervening adhesive or other bonding agent between the ceramic and the polymer feature. For example, instead of separately forming the ceramic component and the polymer feature, and then adhering the polymer feature to the ceramic with glue, pressure sensitive adhesive, heat activated films, epoxy, or the like, the polymer may be molded directly against the ceramic material.

Thus, parts that include both ceramic and polymer components can be manufactured more quickly and with higher precision than would be achieved if the components had to be manufactured separately and thereafter coupled together with adhesive. In some embodiments, the polymer material is injection molded onto the ceramic component. In some embodiments, the polymer material is molded onto the ceramic component using techniques other than injection molding, such as gravity casting, or any other appropriate co-molding process. Where the present discussion refers to injection molding, it will be understood that other molding techniques may be used in such instances instead of or in addition to injection molding."