If you are still accumulating then you should not be selling, but hey whatever, you can do what you like. If you are forced to sell regularly, then that likely means that you bought too much and also that you are trading (gambling) versus investing (at least with that portion of your holdings), and sure I don't see any problem if you at least limit the amount of trading/gambling that you are doing and keep your eyes on the prize which is bitcoin.
We do have two strategies from JayJuanGee on accumulation and sustainable withdrawal. I do agree with your point that one should not sell unless he achieves his desired target of Bitcoin and one must be bullish in accumulating phase to get desired number of Bitcoins. I rarely sell my holdings unless I have some urgent need. One more important thing is that I haven't reached my desired target of Bitcoin but I am still putting all my effort to get there. My investing money might be small but its going regularly into Bitcoin.