It would be unethical of me to offer stock tips in this space, so I'll just phrase this as a question: Why is Wall Street hammering Clearwire Corp.? After reaching a high of $33.30 on July 19, the share price for the WiMax network startup has declined 37%. And on Tuesday the stock dropped 7% "on no news whatsoever," as The Motley Fool put it.Actually, there was news that day related to Clearwire, and it was good. EarthLink announced that it is slashing half its workforce and effectively abandoning the municipal Wi-Fi market. Since EarthLink was the highest-profile company contracting to build citywide wireless networks, its exit has thrown the whole future of muni Wi-Fi into doubt.

How's that good for Clearwire? Well, let's number the ways.

1. The longer cities wait on building Wi-Fi networks, the more likely they are to just forget about Wi-Fi (which is essentially a short-range networking technology) altogether and focus on WiMax. It's amazing, says Carmi Levy, senior VP for strategic consulting at AR Communications, that "not one person in these city IT departments was asking 'Gee, should we be waiting for WiMax?'"

2. The pullback in muni Wi-Fi doesn't eliminate the demand for widespread wireless networks; it underlines the superior qualities of mobile WiMax systems of the sort that Clearwire is building. WiMax "changes the way people use the laptop," Sriram Viswanathan, who heads up Intel's WiMax strategy, told Reuters earlier this week. Ubiquitous, pervasive high-speed wireless access is still a desirable goal and a workable business model. It's just going to take a bit longer than expected, till network builders like Clearwire (which now says it covers 43 U.S. markets) and Sprint Nextel get their systems fully deployed.

3. EarthLink will almost certainly seek a buyer for its existing Wi-Fi networks, at a bargain price. The value of those systems isn't primarily in the equipment, or even in the subscribers: it's in the mounting rights on city light posts and tall buildings. "Imagine a scenario where Clearwire or Sprint built a Wi-Fi underlayment as the entrance ramp to the mobile Wimax network," Ron Sege, CEO of Wi-Fi gear vendor Tropos Networks, told me this week. "You won't need the 40 or 50 cells per square mile that are common in Wi-Fi networks, but you'll need at least 15 or 20 in the WiMax world. In that case, those mounting rights to streetlamps become valuable, and [an EarthLink fire sale] could be very opportune."

It's really not that hard to figure why Wall Street is fleeing from Clearwire (Sprint, which also saw its stock dip sharply on Tuesday, is essentially flat for the week). In the wake of debacles like the Google-EarthLink San Francisco network project (which collapsed this week), anything that has the words "wireless" and "municipal" and "networks" in the same sentence looks like a loser. It's the EarthLink contagion. I'm predicting now that it won't last -- but you didn't hear me say that.