It’s helped to give them national recognition. It had its own line on the college game day song for a good while. People in the east coast, south or midwest don’t particularly care what color Boise makes their field, but they certainly know about the blue turf.
Regionally, opponents obsess over it for some odd reason. Some literally believe it constitutes an unfair advantage (still yet to hear why green jerseys on a green field don’t constitute similar advantage, but let’s not spoil the delusion).
Mission accomplished on both counts. Zero reason for Boise to ever change so long as this remains the case.