I had the same reaction when bike lines were rolled out over London.
The influx of slower and less inexperienced riders with the (correct) mentality of "I have the right to cycle as slowly as I feel safe to", vs the previous (incorrect, but accepted) mentality of "keep up with traffic or pull over" amongst riders, made my cycle commute less efficient.
But it's better now. People learn, the city adjusts, attitudes change.
The influx of slower and less inexperienced riders with the (correct) mentality of "I have the right to cycle as slowly as I feel safe to", vs the previous (incorrect, but accepted) mentality of "keep up with traffic or pull over" amongst riders, made my cycle commute less efficient.
But it's better now. People learn, the city adjusts, attitudes change.