I'm not saying the alternative to frugality is to spend your way to death.
But it's important to remember, if generating revenue is so difficult, you don't have product market fit or even a business then.
Pinching pennies is only valuable in the sense that it can extend your runaway long enough so you can find product-market fit.
It's not a means to an end by itself.
Irrational frugality is pretty much the default impulse of all American software engineers (and the entire HN crowd), so I don't think HN needs any more encouragement to be frugal.
It takes money to build up revenue and get new clients, this are typically called the "customer acquisition cost" or CAC.
The time it takes for a customer to pay back this initial CAC is called the "payback period" which can be 1 month or 10 years.
The longer the payback period is, the more investment you need to bridge the gap.
The business may be super-profitable from a unit-economic point of view, but from a cashflow point of view is a nightmare.
Businesses with long payback windows are very common, but if the theory is that a customer stays for 7 years and you are in the 3th year of your startup, you will have to convince investors that this is true which depending on the fashions of the year they will lean towards true or false.
That's one important point, the other point you mis is that fixed costs cannot be avoided and don't prove anything vs. the viability of your business.
A good example is accountancy costs, office costs and hardware for employees... it's a must to pay for these things but every business needs them but they don't generate revenue.
Pinching pennies is a very healthy habit because again, everybody wants you to spend money (on them).. that's everybody's business model.
Getting a client to spend money on you and getting enough of them to cover the variable and fixed costs is the real litmus test whether you have a viable business.
There are examples of irrational frugality that we can agree on like hiring a zoo of interns that then take up all your attention to manage and train but then immediately quit once they actually get some experience.
Another example is hiring 3 junior devs that can't match the output of 1 senior dev for a combined cost of 1.6 times the cost of the senior dev.
Either way, frugality is a good thing but obviously you need to make the money that you do spend count.
I'm coming at it from the perspective of the irrationally frugal (a common problem I see on HN and how engineers typically behave even when they've found traction).
You're coming it from the angle of the irrational big spenders (VC-funded stuff you hear about in the media ie. WeWork, etc.).
We're both saying: be ruthlessly rational with your time and money.
However, I think a bias towards spending (vs. irrational frugality) is actually much more rare than you think. Everybody knows about WeWork, but they don't hear about all the engineers who spent 6 months optimizing their AWS bill to save $500 when they hadn't even found product-market fit yet.
Curious - what startups are looking at the kind of time horizon for getting their customer acquisition cost back? That seems like an idea that investors would not want to pour their money into unless it’s an incredibly sticky market... in which case, why would they switch to you and not a competitor shortly after you paid for their business...?
I think the crux of OP's opinion is, "it depends". If you can easily save a couple hundred dollars a day and are bootstrapped, do it. Otherwise, it may not be worth it in the grand scheme of things. Thus, no one size fits all, but one size can fit most.
Generating revenue is the hard part in business, spending is really, REALLY easy.