When investing, Im a big fan of diversification of portfolios. I believe that both Ethereum and Bitcoin offer value, albeit in different ways.
Even though Ethereum is positioning itself to become a large platform, the fact that Bitcoin is so well known makes it the first place where people invest.
I think it is not a good idea to convert your BTC to ETH because BTC is still has a larger value than ETH. Also, ETH's value is going low so I think it is not a good idea to convert. If you already have a BTC hold it and don't convert it.