I think they're scared. They are starting to realise that crypto is a threat, and are torn between jumping on board to try to share some of the money, or banning it in an attempt to protect fiat. Most governments are cautious, slow-moving and resistant to change... so they are (most of the time) attacking crypto.
Exactly. Governments have seen how prominent cryptocurrencies like Bitcoin and Ethereum have become, making them believe that this new kind of money will overcome the traditional monetary system. In part, cryptocurrencies have spread out a revolution but they won't be able to replace Fiat in any way. Sometime in the future, governments will use Blockchain tech for their own benefit in order to devise a digital currency of their own.
While physical cash is still being used worldwide, governments will see crypto as a threat more than anything else. Their main intent is to stop money laundering and other illegal activities, but that's not really the case. They just want control over people's money. And crypto greatly prevents third parties from taking any actions against people using it.
Exchanges that provide crypto-to-fiat trading pairs are more prone to be targeted by governments than those which are crypto only. This is because, it's easier to implement KYC/AML regulations within traditional Fiat currencies like the USD and EUR. For crypto, it's another story since identities are not linked within the Blockchain. Most crypto-to-crypto exchanges don't require ID verifications, especially those which are decentralized (like Bitshares/OpenLedger and EtherDelta). That's probably one of the main reasons why governments have been against crypto-to-crypto exchanges.
Still though, the more decentralized alternatives emerge, the harder it will be for governments to be able to implement their own regulations. Which is why, crypto-to-crypto exchanges may become the way of the future, as regulations become tighter over time for regular exchanges with Fiat trading pairs. Only then, people would trade Fiat in a P2P fashion just to get access into the world of crypto. Just my thoughts