On average, entropic embrace comes out to a 1% dps increase over time, which hardly seems "crippling." You have to decide if your visual RP remaining uninterrupted is worth 1% dps. Does it suck that you have to negate your racial to keep your visual appearance from changing? Yes. But this is the only option we currently have.
Alliance high elves, as their own race, is 99% unlikely to ever happen now that void elves exist and have high elf customization. This is the point where it's time to resign ourselves to the reality we find ourselves in, and make the best of the options provided. Blizzard is highly unlikely to add another thalassian derivative race. You'd have more luck pushing for entropic embrace customization (to change or hide its appearance), or even for void elves to get paladins and demon hunters. Those classes are far more likely to be made available than it is for blizzard to add another copy/paste elf race, despite how problematic those classes are for void elves to have in regards to the lore.
I get that this isn't what you want to hear but it's the reality of things and there's little chance that what you desire will come to pass. I'm not saying you shouldn't keep asking for what you want, just to temper your expectations and perhaps try to find a way to make what you do have to work at an acceptable level. But realistically, the alliance high elf issue as been answered and resolved, even if that answer isn't 100% what people wanted. Void elves having high elf customization is a true compromise, and compromise means not getting 100% of what we ask for.
Void elves can have the visual aesthetic of high elves once 9.1.5 goes live. A simple macro can prevent entropic embrace from affecting you visually at the cost of some dps, and its up to you to decide which you value more. A glyph or barber option to customize/hide entropic embrace is a realistic request to make. Asking for another derivative thalassian race is not.
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There's bound to be a few who refuse to take the win and move on, but please don't lump us all into the same box based on the reaction of a few individuals. I'm perfectly happy with my void elf customization come 9.1.5 and have no interest in changing my racial beyond perhaps a glyph to make it look more like Alleria's void form (hers is darker and her hair changes to a different color than her skin). And even without that, I'm still content.
This is enough to make me happy: