When I have questions like this I find it useful to refer to this guide first: http://www.devtome.com/doku.php?id=a_massive_investigation_of_instamines_and_fastmines_for_the_top_alt_coins

It says, of Blackcoin -

"For those of us keeping track, Blackcoin was launched Februrary 24th at 6:00 (no indication is given what time zone this is)). Block 4100 commenced on February 27th at 6:15. In 3 days…Blackcoin produced some 40 million coins (or 50 million). Now they rest at around 75 million coins and only PoS occurs from here.

This is photographic evidence that supports our brief searching of the blackcoin blockchain. The majority of the first 10000 blocks were PoW, and since they were all producing 1,000 BC, the bulk of the coins were made within one week. Anyone should be highly skeptical of the start of this coin. Who would think that the creator of this coin is thinking about enriching your pockets and not theirs?

To this end, who cares about their PoS option? They dished out thousands of blocks at 1000 BC a pop for three days. You would have to hold 100,000+ BC to be able to mint that kind of Blackcoin, which at today's rate would cost you in the neighborhood of $15,000 to obtain 100,000 BC. Are you sure you want to lock in that coin for minting now?"

The author of that guide is vicious in his exposé, and only lists 14 altcoins as being "acceptably mined" (of which Monero is one). Nonetheless, most savvy investors agree wholeheartedly with him and can't fault the facts he demonstrates.