Unfortunately that's not a very good argument on its own. Wifi exists in the unlicensed bands in the US and is thus subject to FCC title 47, part 15 rules. This includes the provision that the onus is on the unlicensed transmitter (in this case your wifi device) to gracefully deal with any interference it might encounter.

At the same time (from the article):

47 U.S. Code § 333 - Willful or malicious interference

No person shall willfully or maliciously interfere with or cause interference to any radio communications of any station licensed or authorized by or under this chapter or operated by the United States Government.

This puts some responsibility on the LTE operator to not stomp on WiFi.

Also, "The FCC has already said that Section 333 applies to unlicensed spectrum by prohibiting Wi-Fi jamming." http://www.wetmachine.com/tales-of-the-sausage-factory/my-in...

While IANAL, the key word there seems to be "malicious". Merely operating in the same band doesn't show any malicious intent, even if it severely degrades performance for other devices in the band.

Jammers on the other hand do intrinsically show malicious intent because they operate in a way which serves no purpose other than denial of service for other local transmitters.

Given that they can't sell these LTE-U devices in Europe/Japan anyway (where rules mandate "listen before talk" like the article says and where vendors have a different standard called LAA), what's the upside in having this just for the US and places like India when experience indicates most manufacturers would rather make one model that they could sell worldwide if feasible? (e.g. almost all GSM phones are quad-band these days and work around the world)

The hardware may be identical and only the software different. They may be able to get away with fewer devices in congested areas if the throughput is better without Listen Before Talk.