Perhaps you're aware that these days VCs are exponentially more likely to invest in you if you have paying customers than if you have a solution you think is interesting but nobody else agrees with you enough to pay you for it.

And I think Ebay was actually making money and showing a clear proof of concept before it got funding. Google began during a period of collective insanity; I doubt they'd be able to raise a penny with a similar starting proposition today.

Cisco I have no idea about.

But as for "all others", not sure what you mean but Microsoft, for example, was making money as a private company before getting VC to help with the IPO process, and the terms they got investment on a clear indication of their cash-based negotiating leverage at the time.

Oracle if memory of my reading serves correctly was making money first.

SAP had paying customers ...

When you say, "almost all other big tech companies" started off with VC as a prerequisite, can you specify what you had in mind?