That assumes that the marginal utility of more bandwidth doesn't decrease; personally I'd rather have 10Mb all the time, than an average of 10Mb that is sometimes 1Gb and sometimes 0.1Mb.
If you can't stream Netflix when it's raining heavily outside, that's a big problem.
I don't think that's the right way to look at the problem. Financial concerns use these microwave networks for additional speed; if it's not available all the time, their competitive edge is limited, but their trades still go through, just not a few milliseconds in advance of their competitors.
At least, one hopes that their trading strategy is based on a combination of financial fundamentals and a technological speed boost; if the speed boost is the only thing they've got going for them then that doesn't speak very well of their business.
My comment was referring to the broader conversation about WISPs vs. fiber for consumer broadband.
I agree that in the financial use-case, the trade-offs are different, and perhaps you can just turn off your wireless link and just fall back to normal fiber when it's raining.
To address your last point, under my limited understanding of high-frequency trading, the edge is in predicting small fluctuations in price, and acting first. For that kind of trading if you incur unpredictable latency, you'd expect to lose money on more trades, since your orders come in after the latency arbitrage has been removed.
You still need to be able to (somewhat) accurately predict those price movements, but that prediction is meaningless if you can't also execute quickly. So the speed boost is a necessary but not sufficient criteria for executing many HFT strategies.
I think that's a benefit to the finance industry, certainly, but believe the OP may have been thinking about using microwaves for normal non-tech-saavy consumer, in which case inclement weather might be aggravating for them.
