Nano is suppressed because it's an existential threat to top cryptocurrencies.
Any cryptocurrency whose goal is as a currency or as a store of value is completely superseded by Nano and no longer serves a purpose. People with large investments know this and will always try to suppress information about Nano.
However, suppression efforts always fail.
Most of the hate against Nano is based on false information, but we're reaching a critical mass of people who are starting to realize this.
Nano will match Bitcoin's current market cap eventually.