Personally, I use my built-in burners all the time.
I send a lot of jobs to the printer. Their courier is in my office delivering things everyday so it is sometimes easier for me to just hand him a DVD with the next job rather than spend the time to upload it and then they have to spend the time to download it plus the maintenance to delete the server copy when the job is complete. Those files are really big.
Also with the DVD version they just toss it in the job jacket so I automatically get another back up.
If there is a problem they can't say that the file was corrupt (unless it was) because there is a read only version that they received.
For our accounting I make back-ups on DVD because that sever is not allowed to be on the Internet. Of course it is PC so it has a burner but just saying I use it.
When we go to trade shows the conference center audio/video techs have regular music CD players that they use to play the background music and they swap out physical CDs when each speaker comes on stage. I burn several different play lists for the various parts of the event.
I often just need a cheap throwaway media to take with me to the copy center. I don't want to hand them them my USB drive that might have additional files on it. I just want them to have only the print files nothing more and they don't even have to return the disc.
I often download the DVD.iso of the CentOS and burn it when building new servers. Sure you can make it boot from a USB stick but it is sort of a hassle.
I could go on but it doesn't bother me that Apple removed the drive. I'll just use some other computer that still has one whenever I need it. Just saying that I still use the discs quite a bit but only when it is an appropriate media. I have plenty of storage in our datacenter and I have also written a really nice file sharing application similar to Dropbox that runs on our server so it is not like I'm clinging to the past.
I realize my usage is not all that typical but I still don't think that optical media is completely dead either. If you want the latest kit from Apple you have to live with whatever they have decided to provide. Otherwise buy something else.