If you look around and read their comments, they are asking people for a justification why people would want to learn Sanskrit in spite of "infinitely many other" interesting things that are supposedly out there to learn. I call this imposition. If you don't, that's a boundary issue :)
His opinion isn't an imposition on you. Not even his opinion on what you should or should not be doing. If you find it to be, that's a boundary issue.