Its likely because you haven't used the platforms that you don't know all the advantages. On Android, for instance, I *love* the new Chrome beta, and being able to share tabs and sessions between my tablet, PC, phone, and seamlessly jump back and forth is awesome, for example.
NFL Sunday Ticket app worked great for when I was on the go, DirecTV Nomad works great on my iOS device, Pulse is a fantastic newsreader with community-based reading features and personalized reading built in, having Tasker to automate tasks on my Android devices is amazing - I have it automatically mute my phone when there's a meeting on my calendar, turn on wifi when I get in range of my house or work automatically, turn on bluetooth when I'm driving around automatically, etc.
I just downloaded an app for the cruise ship I'm sailing on next week that allows me to check my balance, make restaurant and show reservations, communicate with other people on the ship with the app without paying for wifi, etc. Guess what OSes its for? iOS and Android.
Having Google Talk built into all my devices is way better than texting, as I can choose to respond over PC, tablet, or phone and continue the conversation there.
That used to be the case, but BB's getting passed up for email now too. On Android, for example, you can encrypt the whole device, there's remote control and wiping via ActiveSync, and you can even have two different encrypted partitions: one for a "home" mode and one for a "work" mode, so you can keep completely separate environments depending on what you're doing.
The downside of BB really is that BES is unreliable, and everything has to go through Blackberry's network. With ActiveSync, it's a direct connection to the Exchange environment via HTTPS, so when Blackberry was down quite a bit last year, I wasn't affected. You should ask our Exchange guys how much of a pain in the ass maintaining BES is these days.
Apple can replace an iPhone battery in their store for $80 in about 20 minutes or so at the local Apple Store.