I think the best answer is that the service was that bad for those reviewers. Most people don't seem to have major issues though, just as long as you don't expect the buses to always be instant and you allow for up to a 20 minute wait (it's usually less though).
However if you try to leave a park immediately after fireworks, all bets are off! I suggest chilling a while in the park for maybe 30-60 minutes to let the crowds disperse and then head for the bus stop.
The walk from the POFQ bus stop to POR is about 12 minutes (although the total walk does depend on where within POR your room is located). Sometimes it can be worth it, but often not.
Andre