Of COURSE the problem is ownership! That's the first question every worker in my IT department asked when we got offered BYOD!
"So, if I can have company data on my phone (email), what are y'all doing to my phone? Oh, you're putting it in an encrypted sandbox? Oh, you're reserving the right to wipe that sandbox remotely (and possibly my entire phone)? Oh, you're not taking any liability for accidental wipes? Oh, you're not issuing a phone number that hides my personal cell (ala Google Voice/giving me a SIP address)?"
Ya, fuck that noise. Give me my crappy work-iPhone 5 that, rather than using native apps like the Blackberry I had, gets to use "GOOD for Enterprise" apps that don't integrate with the rest of the phone.