While there were benefits of his disclosures, the negatives might not exceed the benefits. Would we (normal Americans) have ever realized that this effort of spying was going on? Probably not - of course we could have blissfully gone about our ways and cared not...until something else brought it up.
Heros are folks I would hold in much higher regard than this fellow but can understand your point! Hero’s today are not the heros of yesterday...Something society has brought to us.