The airlines you mention are neither direct or non-stop except EVA.
I don't know what site you were on but the page you have shown seems strange. No regular Thai airways ticket has a baggage allowance of 20 kgs (23 is the minimum for this route in Economy Class) and booking these flights direct from TG would currently price at 43,520 THB (or 1,294 USD equivalent). I realise prices fluctuate and this is still more expensive than you mention for the other airlines), but if the site you're using is that far out I'd be checking elsewhere.
(Hope I've got the date/times right?)