Something that I'd like to know is, how has their pay changed in the last 10-20 years?
$5/hr increase each year of the contract sounds like a lot by itself - but that's from the view point of assuming that the number you're starting at is reasonable and has been keeping up with COL consistently.
If their wages haven't been keeping up for a long time, then that increase could easily be seen to be reasonable.
About anti-union sentiments: Get rid of unions and you'll be working 80 hours a week in unsafe conditions before you know it. Though I've never worked in a unionized segment of the workforce, unions are the reason that vast majority of us have any semblance of "work-life balance" and are unlikely to be maimed on the job, and anti-union forces are frothing at the bit to work us all to the bone, and it's absolutely disgusting to see hard working men in jobs that used to kill their workers regularly kissing the licking the bosses boots as if they're going to get anything other than a ruined life out of it.
I'm all for keeping an eye on union bosses - organized crime connections, enriching themselves at the workers' expense, but these are largely boogeymen raised up to scare workers away from being in unions; meanwhile anti-union companies have employed all kinds of illegal action including violence and corrupt politicians of their own to get private militia and public military involved in busting strikes but you rarely hear about that when people talk about the evils of unions.