I went through a period where I worried a bit about that, but I've stopped. Regardless of how bioinformatics is structured politically, there's either going to be heavy CS involvement or, well, trouble.

The thing is, in general, a "person" might be able to hack together a small program that works for a particular problem most of the time, but it takes a computer expert to create a program that works essentially all the time, with good performance and strong reliability. If someone in the biology department is capable of doing that, it's probably because they're a "double-major", for some value of the term. A normal biology education will leave them unprepared, and trying to hack together a strong understanding of OpenMPI or something is certainly _possible_ but also extremely likely to leave gaping holes in their education. (Even if one has the brains to become both a biology expert and a parallel computing expert, one must question if that's necessarily the best use of one's time.)

CS keeps making it easier to write programs, but the cutting edge will remain CS's domain for a long time, and academia for some crazy reason tends to like the cutting edge. As specialization continues its march onward it will continue to become more and more difficult to be an expert in both $FIELD and computer science.