Rather than describing the difference between physics and biology as "simple models" vs. "complex models", describe them in terms of expected information content.

Physicists generally expect an eventual Grand Unified Theory to be small in information content (one or a few pages of very dense differential equations, maybe as small as this: http://www.cs.ru.nl/~freek/sm/sm4.gif ). On the order of kilobytes, plus maybe some free parameters.

Biologists generally expect an eventual understanding of a species to be much much bigger. At the very least, the compressed human genome alone is almost a gigabyte; a theory describing how it works would be (conservatively) of the same order of magnitude.

All things being equal, would biologists prefer a yottabyte-sized theory to a zettabyte-sized theory? No, absolutely not! The scientific preference is still MOSTLY in the direction of simplicity.

There's a lot of sizes out there, and the fact that gigabyte-sized theories seem likely to defeat kilobyte-sized theories in the biological domain shouldn't be construed as a violation of the general "prefer simplicity" rule.