I largely agree to what you said, but I don't think that it's wrong for a Bitcoin investor to check the price chart most times, because by doing so he might sees an opportunity to buy aggressively if he has the reserve funds to do so, because he can't be aware of the dip if he is not aware of what's happening in the market, so it's not a bad thing to monitor the chart, what's bad is doing it in excess, because excess of everything is bad.
As for the aspect of being emotional that you spoke of, i don't think it's possible for someone that is only thinking long term and knows the real characteristics of Bitcoin that volatility is it nature, so he will know that it will definitely recovers no matter how dip it fell, it's only a newbie investors that knows little or nothing about Bitcoin will be emotional and sell in panic, not someone that knows all it takes to invest in Bitcoin and be successful.
The reason why an investor should check the price chart almost every time shouldn't be about his investment. Most folks prefer to look at chart for fun sake, while some folks do it because they had an argument or discussion. For example the discussions we carry one here, is enough for an investor to look at the chart maybe to prove a point or something. But if he does that, because of his investment, then is is eventually jeopardizing his investment. Because only traders look at chart consistently, since they do not want to miss out of opportunity every time.