Why are a lot of Republicans (if not the majority of them) against regulations?

The deregulation of US banks caused the last economic recession because banks gave out loans that they knew people couldn't pay back and when they defaulted on these loans and their homes went into foreclosures, the banks lost a lot of money (in a very stupid process). The wasted stimulus money under GWB further wrecked the economy because these businesses had no major regulations in place to limit those CEOs from pocketing the money instead of creating jobs and paying their workers, so they caused job losses through huge layoffs instead.