I think it’s because for console gamers, we usually get a refresh 3+ years into a console’s lifespan.
The Xbox 360 Slim, PS3 Slim, and PS4 Pro came out three years after the originals.
The Xbox One X came out four years later.
Nintendo refreshes take even longer.
And while many will argue that the Steam Deck is a PC, they’re definitely competing for the console audience.
As such, having a refreshed model of the device come out less than 2 years after the original doesn’t feel great for those of us who got earlier models, especially when the two major improvements: battery life and battery, are the two major complaints of the original device and an affordable yet capable device is the main selling point (imo) of the Steam Deck.