I had people literally walk out of the gallery after being asked "So, which of these was taken on a Leica?" when I correctly and honestly answered "None, sorry.".
Also my prints are usually a mix of various lenses, sometimes even developers and film stock. Not by choice, but simply due to availability. Or me not wanting to take my most prized camera/lens into a raging typhoon/snow storm. Yet, no one has ever commented on this, neither publishers, nor curators, customers who bought prints or the gallery visitors (amusing Leica tantrums aside) So I have to conclude that either your friend is inexperienced at darkroom work and you ascribe to lenses what is lackluster darkroom work, or -- you are just making stuff up.
Also, I do not dislike "gear chat". Quite the opposite, I like to jabber about gear as much as the next person, but there is this insistence that good pictures can only be taken with X Y and Z. This is absurd and is as Brian already pointed out, close-minded; worse - it is also bloody boring since it cuts the legs out from any discussion. "X is best, case closed!" Wow, such deep insight!
Lastly, photographically speaking it is also simply not true.
There is no "best" - there is no ultimate answer to the question of "What is the best lens/camera?" Why? Because the question itself is silly. Best for what? Best in what regard? Best for whom? Best for when? Best amongst what? ..et cetera And thus we can safely conclude that people who insist otherwise are full of it. Furthermore, the act of photographing requires intense inquisitive curiosity - excluding entire countries lenses because the name ring does not say "x", "y" or "z" on it is the opposite of curious.
I have seen people post amazing stuff taken with triplet lenses that were made well before modern Germany, let alone Leica even existed. Everyone has their preferences and kinds of gear they like, but that does not mean that it is "the best". Imagine an artist or draftsman getting upset about which type of pencil someone else uses - yet here we are ....