Maybe the OP just created this thread with the aim of earning merit, but since he was not able to earn merit through this thread, that could be the reason why he stopped being active in this thread. I just checked the OP profile, and I noticed he was given a negative tag for bounty cheating, which could be another reason why he stopped being active with his account in the forum. Even though the OP is no longer active in this thread, it doesn't matter; the most important thing is that there are a lot of people who are very much interested in contributing to this and helping people who are interested to learn about bitcoin and also invest in bitcoin to achieve their aim without being burnt on their bitcoin investment.
Everyone does have their own reasons for everything, including being active and inactive in this forum, but I personally don't see it as a serious problem because when a topic can still be active without OP, of course everyone can still discuss here according to the ongoing discussion. And by the way, at this time the price of Bitcoin has also corrected again from $102K to $93K which can be utilized by Bitcoin buyers because the price is already quite low. Although I also don't know why the Bitcoin price correction happened suddenly like that at this time.