One other point.
I know that there is some gear that should be perfectly acceptable by anyone who knows anything about it. However, many BEs are not gearheads like us. They don't know ever make and model of mixer,compressor,amp,speaker made over the last 25 years. They also don't have experience with everone out there.
They know what works for their band. They know that companies like EAW, Soundcraft, A&H, Midas, Community, Trubo, Nexo, JBL, etc, etc. make the some of the top end gear out there. They also know that Makie, Peavey, Carvin, and Behringer don't. They make good to great MI gear, and some mediocre pro gear that may be a good value.