Old school pickers and collectors who sell are far different from the new breed of pickers who are easily fooled by fakes and ask 3 times retail for their items found in plain sight. You have too much knowledge and passion for the hobby to be a new breed picker.
I miss the now deceased picker who sold me a dozen items over the years. He would remember what I liked and would let me know when he found something that fit my interests. He found items for me that I have never seen for sale elsewhere.
Shake it off, John. Consider the source of harsh criticism. If they don't have the unblemished standing to be taken seriously, don't listen.