It is not only the bitcointalk but the whole BTC community (including the traders) turn bearish when we are hitting these so-called psychological resistance. These resistances are here for the obvious reason and that is to serve as a gate before BTC surpasses it. Most of the time, people will set their sell orders in these resistances putting a stop on BTC's run for a while. I must say that this is very important if we want to see our beloved coin to soar higher. Again, these are just "psychological" can be overcome if the community changes its state of mind regarding that specific price.