The Power of Sale - what use if not used?

I have been advising on a lot of insolvency transactions of late; now there's a surprise. One thing that does continue to surprise me is banks' unwillingness to sell by use of their power of sale. Let me explain . . .
When a bank takes a mortgage over a property it will, normally expressly in the mortgage and also by statute, have a power to sell the property. If it sells the property then not only will this automatically release its own mortgage but it will also overreach (get rid of in layman's terms) subordinate charges and other encumbrances created after the bank's mortgage and without it's consent. A sale by a receiver or administrator will not have this effect. Therefore, on the face of it a sale by the mortgagee is the most effective way to transfer the property clean. So why not always use it?
I think there are two reasons. One is incorrect and the other is a case of shutting the gate after the horse has bolted.
The first is that mortgagees are rightly concerned about becoming a mortgagee in possession as this creates a real risk of liability. This is a big reason why mortgagees appoint receivers. During the boom banks became so unused to the idea of powers of sale that they now misunderstand and think that exercising a power of sale requires a mortgagee to be in possession - it does not.
The second reason is that banks do not want the bad publicity that goes with foreclosure, repossessions, etc. They believe that if they sign the transfer deed they will be outed as the nasty bank repossessing peoples' homes.
Why is this a case of "shutting the gate after the horse has bolted"?
Well for starters I am not sure that banks collectively could do much more to damage their current reputation (rightly or wrongly) of being greedy, short-sighted and generally responsible for the disastrous global financial mess we are in.
However, on a more individual basis, does a bank really believe that hiding behind a receiver protects its reputation? Do they really believe that, when a receiver sells, we don't know that it was the 'nasty' bank that put them in place.
So come on banks, if you are going to repossess peoples' house at least have the guts to do it in openly - we know who you are anyway - at least that way the buyer has a better chance of getting a cleaner title.