I think a simpler explanation is that IPOs simply weren't a good idea for most technology firms, which is part of what led to the dot-com crash.
Google, Microsoft, Nvidia, Apple...No Debt.
The existence of large cash cushions on these balance sheets is insurance against a rainy day, and changes the risk profile. If these companies had been levered during the 03-07 expansion, they would have exploded in value.
They didn't, because it makes no sense to lever a tech company to the hilt, even if you believe it makes sense to lever a manufacturing company to high heaven. Cashflows are too variable and too prone to disruption.
It takes a special kind of tech co to go public, and many (i'm lookin' at you pets.com) weren't that kind.