HTC has never been more, nor wanted to be more, than a parts assembler. That just isn't enough these days. Even the hardware manufacturers must involve themselves in ecosystem development. They must also push the limits of what is possible through real innovation (meaning research investments, filing patents, buying innovative startups, designing custom ICs etc). HTC hasn't meaningfully engaged in any of that... not for WP and not for Android.
HTC's understanding of innovation is limited to being the first to market with a new (but off the shelf) component. A new Qualcomm chipset, a new display panel or whatnot. Being entirely focused on hardware, industrial design is also central to their efforts, and despite them doing some great stuff in that department, it isn't objectively better than what Apple or Nokia achieve.
HTC is on a slow path to their own demise. IMHO their board is incompetent and should be fired. Unfortunately, I suspect HTC will be sold before that happens.