Eh, no.
If there's a problem it is in the mismatch - that you and the player want different things. But that doesn't mean that what either of you want, in and of itself, is a problem.
I was going to fight you on this; it sounds like he's describing using the DM, the table, and the game as props in his solo exercise. But you do have a point... if that's the game everyone is playing, they're competing/collaborating in that kind of gameplay, and the other players trying to act out
their personal stories using the table as their stage are part of the game. That can be fun. D&D is a good enough ruleset for enjoying that kind of game.
I don't often see it working that way in practice. Could be a cognitive blindspot, or it could be traveling in different social circles-- or pure dumb luck-- but I mostly see the people who
want to play that game resenting the DM and the other players for wanting to play that game with them. Demanding spotlight time for themselves, wanting the game to cater to
their storylines. Most of the people I see arguing for the compelling need to have at least one full letter-sized page of backstory don't want to play that game, and aren't getting anything out of those long, dreary backstories... they just
believe they're necessary because they learned to play in a certain era, shaped either by the narrative roleplaying trends of the 90s-00s or the Actual Play culture of the 10s and 20s.
And I rarely see it benefiting anyone but the people using them to hold games hostage. People who
want deep, character-driven immersive roleplaying get
more of what they want when their backstories are short and succinct enough that the other players can remember them, and intertwined enough that the other players are playing with them. People who just want to play casually don't have to write or read useless word count that only two people at the table are expected to know or care about. The umpire who has everyone's relevant narrative hooks on a 3x5" index card has less trouble weaving everyone's story arcs into a shared campaign, which makes everyone happier.
Mandatory, elaborate backstories add very little to the games that most people insist require them. If the people advocating for them
actually benefitted from them, then we'd actually be talking about people who have different gameplay expectations and preferences. Most people playing D&D, the way most people play D&D, would have a
much better time playing D&D if they either created their characters much more casually or much more formally. Less effort for bigger rewards.