You don't want to play hardball with a player over a 25% change in salary? Even accepting that Wilson took a step forwards, $1.5M is a significant raise and 50% higher than his QO.
The only comparable the $2M camp is offering is Jason Zucker. If a comparable like that was used in arbitration (which Wilson didn't even have rights to), it would be easy to disprove why it's a band comp. Zucker had 13 goals last year alone. Wilson has 14 goals in his career. Zucker had a 21 goal (in 55 games) season before that, and is a 0.25 G/G, 0.36 P/G player in his career. Tom Wilson is a 0.06 G/G and 0.216 P/G player in his career. Zucker is a far more productive forward who also had much more leverage in his negotiations (he had arbitration rights) than Wilson did. He should be paid more than Wilson.
The bulk of players who earn $2M on their 2nd contracts are far more productive players than Tom Wilson. Marcus Johansson, Colin Wilson, Brandon Sutter, and Andrew Shaw all earned $2M on their 2nd contracts.