Brostek is a stud and did well playing as a true freshman (minus the pass-blocking).
However, the physicality, speed and technical aspects of the college game are much, much harder than high school, and the position has the highest learning curve of any position besides QB. All OL should be redshirted in their first year because they need time to build up their strength and speed and even more time to learn how to read defenses and pass-block correctly. Sure, if they're big enough, they can do well at run-blocking but they're going to get blown away in pass-protection because defenses are more sophisticated and players are that much better. If you want two recent examples of this, look no further than UW in 2011 (Porter started at RG, Kohler at RT) or UCLA in 2013 (3 true-freshman OL starting, Hundley sacked 3 times per game).
Redshirting Brostek now is a bit of a waste in the fact that he has had time to adjust to the physicality and speed of the game now. However, it makes sense considering a number of other factors. Sark moved Brostek from OL to DL last year for whatever asinine reason, so spending a year on the sidelines will help him redevelop his skills as an OL and help him with pass-blocking. Redshirting him in 2014 would mean he could then play in 2015 and 2016. We're losing 5 OL this year including 4 starters, meaning our starting OL next year will might look like:
Eldrenkamp (rs-JR)
Charles (rs-SR)
Tufunga (rs-SR) OR Crane (rs-SO)
Brostek (true-SR or rs-JR)
Dolbec (rs-SR)
If we redshirt Brostek, we'd only lose 2-3 starters next year. Otherwise, we lose 3-4. As you can see, losing a potential of 7-8 starting OL over 2 years is a significant hurdle, so developing depth this year and next will be essential. And one of the best ways of doing that is to preserve a year of eligibility for Brostek. And it makes sense because it won't cost us anything this year and pay huge, HUGE dividends in 2016.