Disclaimer: I played baseball in college (was a PO - a pitcher only), have followed it closely my entire life from college to predominately the MLB. I would consider myself above a casual baseball fan. I totally feel everyone on the frustration. However, there is no rhyme or reason why anyone should be upset with your starting pitcher (who was throwing a great game by the way) staying in the game in the 5th inning with a massive lead to save bullpen arms for the rest of the weekend. College ball is different that major league baseball in how you construct a pitching staff. Your 4th and 5th guys in the rotation typically throw during the week, you save your ace and bigger arms for the weekend series. The opposite is true for the bullpen. You want to have bullpen outings during the week and work on development for your younger arms and spend the weekend trying to minimize damage to the pen.
All that being said, there was absolutely nothing wrong with keeping Forbes on the bump in the 5th even after walking a few guys. Folks, we are in March. There is absolutely no reason to burn through your bullpen on the Friday of a series in conference play when you have a huge lead and a full weekend of ball ahead of you. ESPECIALLY knowing Cal hasn't thrown their top arms yet, meaning you are going to struggle to produce more runs and on the other half of the inning, keep enough arms alive to win the series. There is way more to managing a 50+ game season than pulling your starter in the 5th with a massive lead on the Friday of a weekender. Again, totally feel the frustration but to say there are issues with Mac's management is ludicrous. If you want to talk about talent, that's another ordeal. I don't see this staff being as deep as they have been in years' past.