In other words, one has to be a good poster first to earn a vote for DT1, while possible trustworthy members with less meritable posts are sidelined.
True, and this is a potential drawback of the new system. However, I would argue that if you are a proven trustworthy member, and have been here for any length of time, you would have absolutely no problems earning 10 merit, which would give you both a vote for DT1 and the potential to be elected to DT1 yourself.
There are plenty of users with high activity who have farmed it by just spamming in Games and Rounds -
such as all these spammers. 500 days spent spamming Games and Rounds or ICO Announcements isn't worth 1 day spent in Meta, reading the stickies and learning about the forum.
That will sadly do you no good because if someone with 250 cycled merits does not want you there it is likely they will collude with the small circle of pals to get you removed.
250 earned merits are the key positions in the trust system.