Locking someone up for 30 years is more or less equivalent to a death sentence - society will have progressed so much during this timeframe that the convict will never be any productive part of society again. At that timeframe, seriously, it's more humane to give the convict a gun with a single bullet than lock him up for 30 or more years - and many people are locked up for longer for non-violent crimes.
Then again, the US is barbarian enough to lock up juveniles for life, so people saying "30y is not enough" doesn't surprise me in the slightest.