It can be, but the divide isn't as pronounced as it was in the late 90s and early 00s. I know that RTL engineers tend to make more than most software engineers nowadays.

My previous housemate worked in the tech recruitment industry, and he told me that the top end of the semiconductor industry tended to always pay better than the software industry, provided you excluded finance from the mix (where hardware engineers don't generally get a foot in outside of designing chips for HFT). Equally, though, the bottom of the scale was lower.

My personal experience supports that conclusion. As a graduate, my starting salary was dramatically lower than my university friends who went into software, but the jump in pay between grades proved to be much more dramatic.