Who calls themselves a grognard? It has connotations of stodginess and fear of change and is generally used to denigrate people for being behind the times when it comes to gaming. And who wants to earn the respect of people who gatekeep the term from people they don’t think are old and stodgy enough?
Old and grumbling has a certain air of prestige to it....
And where did fear of change come from? I play 5e and I've been considered a grognard.
I think the pendulum of grognard being derogatory has swung to far. Some 3e players once told me I was the best grognard they had ever met, after I dm'd their 3e game for them.
But that's just my opinion.../shakes stick at everyone.