Why can't Homomorphic encryption schemes support algorithms with conditions/branching? If it isn't already apparent from the title of my question, i should make clear that I have only a very basic understanding of homomorphic encryption. 

I would like to know why homomorphic encryption schemes cannot support algorithms with conditions/branching, and what the likely impact will be on the overall adoption of HE schemes. Given this limitation, are HE schemes likely to be useful in real life? Thanks.
I think you have a misconception.  Fully homomorphic encryption can support algorithms with conditions and branching.  Any such efficient algorithm can be unrolled to be implemented as a circuit (say, with just AND and NOT gates), removing all conditions and branching, and thus can be implemented on encrypted data using fully homomorphic encryption.

Of course, fully homomorphic encryption schemes are hardly practical right now; search this site for more details.