It's both, and then some. Product folks surely do love to get new features out. Developers also love it, because writing new code is far more fun than improving reliability, performance, security, or operational load for old code. In 30+ years I've worked in all sorts of environments, but accumulating technical debt has been one of the few constants. Everyone tries to say the right things in meetings. Maybe tech-debt reduction even makes a brief cameo in early planning sessions, but good luck getting it into the final plan. Even if that happens, guaranteed that it will show up as a miss at the end of the cycle, because it's always the very last thing on everyone's list and everyone's list is always too long. A dozen companies, maybe twice that many projects, twice again as many architects/managers/whatever, always the same story.

As for "and then some" that's the part that's on senior management and HR, for setting up review/promotion structures that actively incentivize sloppy engineering. When all of the rewards are for New Shiny, some people will actively sabotage efforts to spend time any other way. Nobody wants to delay their new-feature effort to deal with new test failures or cleaned-up APIs. Even those who have enough of a conscience to to the right thing get kneecapped at every turn.