1) Jobs hates optical media, and is on a crusade to kill it (see recent mini update, refusal to add Blu-Ray, etc.)
2) Flash based media is much faster and much more resilient than optical media (ever had a disk rendered unreadable by scratches? It especially sucks if you don't have a backup)
-Don
Point no.1 everyone can agree with.
Point no.2 yes, flash based media is faster, but not by that much, with ~30 MByte read on a good flash-ROM vs. 22 MByte read on optical DVD drive. Flash has better seek time (i.e. near to none, but that doesn't matter so much for an optical disk meant for installing, there are very few times it needs to seek)
But being more resilient. That's not so correct. Sure disks can scratch (although BDs not so much), but so much that the disk is unreadable - no, I've never seen that. Sometimes a file or two become corrupted if the scratches are serious.
A flashROM either works or not. When it fails it fails completely 100%. When a disk fails, it's less, 1% or so.
In this discussion we are talking about commercially made DVDs vs. ROM.
A printed DVD is physically etched with every line of data, it is forever. It's not comparable to burned DVDs, for instance. And flashROMs aren't invincible either. They die if they get wet, a DVD can just be cleaned.
It's not so clear cut advantage to flashROM, and when price is added to the equation, I'm sorry to say, optical media is so much cheaper. FlashROMs are a luxury item and in the end no more reliable than a DVD/BD. More difficult to store perhaps and easier to lose.
