RE:Making sense about POET Welcome chipguy! Where were you when we needed a real expert 4 years ago? :)
Here's how you're wrong:
1. There are no 12" III-V wafers. All state of the art chips are made on 12" wafers. Do some research on the size of wafers POET is using and you will know what you need to know. Not scalable.
The wafer size is irrelevant when you can combine the function of multiple chips onto one single chip. Not only do you save on the number of runs, but you may also save on packaging which is a huge cost and also a source reduced yield for the total package. An application where POET is attempting to make inroads (the so-called 'low hanging fruit') is in the optical transceiver. Here, POET can reduce a 9 chip assembly to a single chip. The benefits are obvious...
2. POET's IP does not cover doping silicon wafers for III-V, its all III-V wafers. So their IP won't get bought by the big chip companies: Intel, Samsung, Global Foundries, Micron, TSMC.
POET has developed a process which can make use of shuttered Si CMOS fabs currently gathering dust and costing money. The fact the POET starts with a III-V wafer doesn't have any implications for adoption if the total cost of manufacture can ultimately be reduced (See response to #1).
You are correct if you are implying that these companies would prefer a Si-based solution, but this isn't correct for the reasons you think. POET is the first III-V answer to Si-CMOS complementary logic. I'll say more about this below.
3. III-V wafer applications are being obsoleted by SOI. Silicon on Insulator. The only thing left for III-V now is power apps. Therefore, there is not a lot of money being put into III-V.
I mentioned above, POET is the first to offer another kind of complementary inverter in III-V. Historically, the p-channel was too slow in GaAs to stop the current without large leakage. POET solves this problem. You are correct that SOI is supplanting III-V for many applications, but those applications are very limited at present. Complementary login in GaAs opens up new possibilities that have not even been dreamed about to date.