If you look closely at my history anyway you'ìll find that I spent many months on the forum almost inactive. Only later, once I found the way to contribute to the community, did that meriting start happening.
Speaking about merits then you are right on the part that there could be instant rally or slow growth over time and in my case also there was long delay in ranking up as was not having adequate knowledge till then but once I started learning new things and focus on improving my posting style the merits were given but there are some members who loose hope fast when they don't get merits but they need to realise with time they can achieve it and this thread don't focus on copying you style but just take an inspiration from it to continue their forum journey.