A few changes have happened: explosion in number of systems, decline in quality of NSA staff (due to better opportunities elsewhere) on the tech/IT side, increase in contractors (who also tend to suck), politicization (since in the 1990s there was no clear mission, and in the 2000s there was not as morally justifiable a mission).
The NSA IT people I've met in the 2000s would not be people I'd hire to do IT/security. The older "former NSA" people I know are people I would gladly work with.
2) It appears Snowden has somewhat overrepresented the level of access he had.
The correct solution would have been using more military people at NSA and accepting a much longer in-house training pipeline. The benefit is I'd trust an 8-12 year military IT veteran who served in general military IT then got put at NSA a lot more than someone hired as a contractor; much harder for the enemy to infiltrate someone, and someone who has been in for 8-12 years probably has a pattern of behavior, family, ties, etc. to make it less likely he'd accidentally or intentionally fuck you.
Schindler seems to be particularly upset (which is probably understandable) and maybe not representative of how people treat contractors normally :)
The problem is that it's expensive and much more difficult to administer, but hopefully NSA and DoD in general will realize why mere difficulty of administration should not hold them back now.
Honestly the NSA is lucky that the first (known?) insider leak of this type came from a do-gooder instead of something more sinister.
I will say that civil servants tend to despise the contractors. I can't say I blame them either, it's literally a case of "dey turk our jeerrbs!". But fixing the rise of contractors would require both a decoupling of the military-industrial complex and possibly an overhaul of the civil service benefits/retirement scheme (as the whole point to hiring a contractor is that their staff are cheaper overall).
You could keep a civil servant for $80k/yr and give him a $60k/yr pension for (say, $120k/yr for his working life) for an entire career of 30 years for that. Spend the first 5-10 on training (much of which is OJT, so he's still doing useful work), and you're still 10-15 years ahead, even today.
I wish NSA would separate into COMSEC and SI at the agency level.
Essentially every military officer is S or better, I think, and virtually everyone in certain military units is S (IT, etc.) or in some cases TS (CI). That is a lot of people. A lot of 18 year olds :(