Based on some philosophy people mentioned that when Btc raise, most of the alts drop
But look at the top 20 coins in cmc
Dash
Eth
Ripple
Monero
And even Doge
DOGE GROW 18%
Any particular reason?
Perhaps one of the reasons for this is that as the btc price grows, people become more acquainted with cryptos in general and sometimes, as btc is already too expensive, they start buying other crypto-currencies. I think this theory is more right than the one you are talking about.
However, in a way, there is no strict connection between btc and other currencies, so abything can happen. Perhaps if something happens to btc other alts will drop, but the opposite might happen as well.