Assuming we're talking about the US, I just don't see how that assertion can hold water. 2000 hours per year is a widely-held rule of thumb for "full time" employment - 40 hours a week * 50 work weeks per year. 1500 hours means you average a 30 hour work week or take a tremendous amount of vacation - neither of which sound anything like the employment situations for "most software engineers."
I understand what you're saying though. It's a lot "easier" to go to school for four years, make $90-120k and have $0-40k in student debt than it is to go to school for a decade, make $125-175k and have $80-150k in student debt. But truthfully, when you have that kind of buying power you can live like a student for just two more years and completely pay off your debt (or very close to it). Software developers usually don't have that kind of buying power. Outside of the Valley and NYC an entry-level developer may only make $30k a year. Even a $200-300/mo student loan payment at that income is tight.
$125k may not seem like much to anyone on here used to Silicon Valley prices. But that's more than my parents paid for their very nice two-story home with a massive backyard (large enough for a pool, a large shed, a fort, a kennel, and then plenty of open space to spare). My parents' home was big enough that they had a reputation for being rich in my hometown as I grew up even though their combined income was about $80k.
Even after that though, they make around 125-175k. Most doctors do not start making over 200k until ten or more years of practice. And again, that's with around 1500-1900 hours per year, which is considerably more than most software engineers.