I don't know what HTC is doing in the USA, but they're doing really bad here in South East Asia. Doesn't matter which country you go to -- Singapore, Philippines, Hong Kong, Malaysia, Thailand, etc. Less and less stores are carrying HTC devices and HTC concept stores have closed down. The biggest problem I see for HTC here is their pricing. Their cheapest starts at around $200. That's not a good way to get market share. Another part of the problem specific to this region is the availability of "rebranded" OEM devices from China. For about $250 to $300 unlocked, you can get a MediaTek-powered phone (specifically the MTK6592) which has the bells and whistles of upper-mid range phones which cost over $450. 1080p display, 2 GB RAM, 32 GB ROM, 13 megapixel Sony Exmor RS camera with f2.0 lens, expandable storage, etc., all for around $300.
The first thing I'd do is restructure the product line-up and pricing. HTC has virtually zero presence in the low-end and their midrange line-up has terrible pricing due to poor specs. There are more than one ways to differentiate on Android, but completely ignoring specs is not the way to go. Apparently, HTC thinks they can sell poorly specced devices at premium prices simply because of a more premium build. Also, HTC has yet to create a brand image that can command such a price premium. A more robust spec sheet takes priority over finish and build at lower prices, especially if you don't have the "pedigree" of brands like Sony or Nokia.
Take the HTC Desire 610 and 700 for example. Their street prices here are around $340 and $420 respectively. You compare it to offerings from Sony, Samsung, Huawei and other competing international brands at the same price range and hardware-wise, they get trounced hard. And compared to rebranded phones at half their price, they still get trounced!