Its not that hard. Just say:
Welcome criticism
And much thanks for your response of criticism.
I'm certain that had it not been for the strong critics, Massage Planet would be making slower progress.
"For myself, I have come to set high value on the posters who have criticized me, whether they have seemed reasonable critics or unreasonable ones.
Both have often restrained me from doing, much worse than I actually have done.
The unreasonable ones have taught me, I hope, a little patience. But the reasonable ones have always done a great job for massage planet.