I can give you example of so many users who are earning merits but not doing these self praise type none-sense BS just to whore merit. Yes it is just a dirty way of whoring merit. Look at fillippone, LoyceV, o_e_l_e_o, El duderino_, DdmrDdmr, suchmoon, LFC_Bitcoin, pooya87, gmaxwell, JayJuanGee, The Pharmacist or even theymos and many others. Find me few topics from them that are garbage self praising, showing off with bold head.
You have a good point here but we assume good intentions unless otherwise proven, however too much of these thread will not be helpful.
Creating a single, self-moderating locked topic with My Achievements List title and updates it periodically is suitable for those who like to share their achievements.
If you see someone spreading spam in this way, you can ignore that person.