Well, you do have the problem in most science fields (except the theoretical sciences) where it costs a lot of money to run experiments, so it's not just something you can do in your kitchen.
Are you certain? See http://openwetware.org/wiki/DIYbio/FAQ/News
In general, though, we're still chasing the long tail of knowledge. Nobody's going to build a cutting-edge particle collider, space probe, or Inca ruin in their spare time.
Arguably microbiology is a lot more like computer science than other experimental sciences economically, at least in certain respects; for example, once you've got something interesting, you can probably execute a fairly cheap reproductive process and get a whole bunch more of it. (Well, this is cheap compared to reproducing a particle collider, at least.)
Fun to think about.
Doing research in biological sciences often involves millions of dollars of funding and just isn't something that can be circumvented. My girlfriend is currently pursuing a PhD in Neuroscience. Studying that brains of hundreds of animals isn't something that I'd want her doing in the kitchen.