I don't think 'good looks' matter as much as 'clean looks'.

Shave. Shower. Get a haircut. Despite the 'hoodie chic' look, make sure it's a clean hoodie. Or better yet, wear something nicer. (no, not a suit, but a step up from a hoodie will help people take you seriously).

As far as general likeability goes, usually that stems from people either complaining or saying offense things.

All of that is under your control.

Body posture is more important than actual innate attractiveness. Body posture creates attractiveness.

People's natural tendency to associate good looks with intelligence, etc. has been documented (IIRC), but I completely disagree that it cannot be overcome if YOU decide you will "fix" it.

Example: Sean Stephenson http://timetostand.com/ (see short video)

Not attacking you personally - but anybody, .. anybody at all who gives me that response are basically chickening out. Consider this the opposite problem of "business guy don't want to even learn how to code, give all sorts of reasons". Technical guy don't want to learn how to hustle, give all sorts of reasons. Again, Sean Stephenson.

Yeah this is not meant to be an excuse at all. But it used to be that code/innovation mattered more than words, PR etc. Certainly the oldest tech companies were of the "build it and they will come" type. If nowadays who you hang around with matters so much, does that mean that information tech has somehow already peaked?

Customers don't care about your cool technology, they pay you to solve a real problem they have. That has always been the case. If you see a successful company with cool technology, it's because it ALSO solved a real pain the customer had. There's plenty of startups doing "cool stuff" but it doesn't solve a problem, and therefore it doesn't go anywhere.

So I'd reframe the question: it's more about solving real problems. If you can solve it with cool new innovation/code, great. I assume the goal we're talking about here is to build a for-profit business.

Well yeah, look at all the hot startups out there. Except for a few orgs at the extreme high end of tech, a YC style startup is a marketing project with basic IT. Dropbox and a couple others might be an exception.

I was at an academic conference earlier this month, and several of the speakers made affectionate jokes about one of the speakers - how he couldn't shut up, how he was impossibly argumentative, how he was terribly rude, and basically how he was a bit of a troll. And they were right, he was all those things, plus he looked a bit like a frog. Imagine a short frog with glasses, a thick Noo Yawk accent, and the social graces of a falling brick.

And yet he was such a persuasive and entertaining speaker than even when I thought he was dead wrong I wanted to hear more and find common ground with him. I liked him even when he was being an ass, and even in cases where I knew he was wrong (eg when he deliberately skipped over some significant issue because it undermined the argument he was making).

The things you mention help, but are by no means essential. You don't even need to believe in yourself, as long as you believe sufficiently in your idea.