People that grade coaches solely on win/loss records are a little shortsighted. Taggart came into two bad situations at WKU and USF, and turned them around. WKU was a transitioning FBS program, they were getting crushed when they first arrived to the level, Willie had them bowl eligible before he left. In essence, he set the table for Petrino's lone year, and the success Brohm has found there(I'm still shocked Brohm didn't get any love from bigger programs, he is quite solid and Purdue is a dead end gig). USF was awful during the Holtz era, he inherited a solid program from Leavitt and turned them into pure garbage. Taggart once again trended upwards every year, ending in a 10-2 year this year, USF's first ten win season ever.
Do I think that Taggart is a splash hire? No, but he has the chops to get Oregon back into the Pac-12 fold(I don't see him as a national championship coach, the Chip Kelly era was an outlier for Oregon), he's an upgrade over Helfrich, who most likely shouldn't have been promoted in the first place. It's rare that an assistant is promoted to the top job, and has success in that role. Switzer succeeding Chuck Fairbanks, and Tom Osborne succeeding Devaney happened decades ago. The only relatively recent example was Mike Bellotti at Oregon, and even then, he was solid, but not spectacular. Willie's offense should fit in well with what Oregon wants to do, he does place a premium on speed and athleticism. Oregon made a solid hire, that worse case scenario will have them be a 7-9 win program. Historically, that's what they've been, outside of a couple of pops under Kelly, Belotti and Rich Brooks.