Geth – How to Run Geth for Ropsten and Mainnet on the Same Server

A rather weak argument against your suggestion is the following: The deployer would have to use the same private key in both test and main net. This could be considered a security risk, as private keys in test net usually do not have to be stored and handled securely, while in main net they most definitely do. Mixing the two domains would, thus, blur the security requirements of each of them.

I would argue, though, that the pros of having the same address in both test and main net are not very convincing either. In the example you linked a better solution would, in my opinion, be passing the respective address in the constructor.

Also, not all net-specific code would be made obsolete anyway (e.g., parameters such as crowd sale durations, validator numbers, ...).

I'd suspect this is what has happened.

The current hash rate (as of Ropsten block 673252) is 0.011 GH/s, with the difficulty being 134,588,276.

Prior to the recent spam attacks, if we take block 586946 as an example from before the attack started, the hash rate was ~0.005 GH/s and the difficulty 105,432,944.

The Ropsten testnet was rescued from the spam attack by the donation of significant hash power, which was able to mine a completely new chain starting from before the attack, and replay all the transactions since. I'm suspecting that some of this hash power has remained in the network to help prevent the attack from reoccurring.

You're now mining in a more competitive, but safer, test network.