My kids definitely don't have that problem, despite the PB&J allowance - so it isn't the PB&J allowance that is causing unreasonable levels of pickiness in the children you know. Mine eat pad thai, palak paneer, smoked salmon, kim chee, calamari, sushi and snails. (Last time we went out to a place that served "slugs" they comp'd my eight year old daughter's dessert - the entire kitchen was standing in the door to watch an eight year old eat escargot.) They eat them with varying differences - she'll eat snails and squid - he passes, he'll eat pad thai, she sticks with satay. More traditionally, he'll eat chili, she won't touch it, he passes on broiled chicken. They definitely aren't "picky" eaters in the traditional sense of "nothing but mac n cheese and PB&J" - however, there are foods they don't like (and, in case you can't tell from the above, we have presented some challenging options to our kids over the years - there are adults with more limited palates) - and PB&J allows us an option that keeps everyone content.