The "better" alts are typically only "better" for a matter of minutes or hours lately. Not really viable unless you're auto-switching. Litecoin is still a wash, if your pool also mines NMC. This will likely be the case until ALL GPUs are mining LTC. However, that point may be after GPUs are completely unprofitable.
This statement points to a big portion of the picture that you seem to disregard and misunderstand. Auto switching is actually not a good way to go IMO, because the alts do bounce around and you mine on the upside... you need to mine one of them and wait for the upside to come after you already have coins. I have been watching a few alts that have remained better than LTC for several days, they bounce down to near LTC, and they come back up and let me know when to trade. Another cornerstone of your argument is that price will not rise with difficulty. Now, I know that price and difficulty are not directly related, but look at the long term charts and they match up perfectly. So to disregard the idea that price rises might keep gpus mining longer than you expect is not something I can agree with. You do make some good points, but you disregard variables in favor of your own assumptions, which may or may not be right. At the end of the day cryptos are a hobby, what do you care how anyone else does it? Besides, people have been screaming gpu mining is dead for such a long time that you shouldn't expect anyone to believe you now even if you are right
Timing is critical with your method, and you're basically speculating and timing the market. You may as well just buy the coin you think will rise.
If you believe BTC price will rise, buy coins rather than GPUs. Difficulty will certainly rise quicker than price; hence it will ALWAYS be more profitable to buy coins directly than it is to buy GPUs, if you believe price will rise.
Of course I expect at least some people to believe me...otherwise why post at all? If I help even one person avoid losing money on GPU mining, it's worth it.