Most of these obscure short names are chosen because #1 the domain is available and #2 they're hoping they can somehow brand them.

Name does play a role in the success of your company. However if your product sucks then a good name isn't going to fix that. If people can't remember or spell your name, that can kill your word of mouth marketing.

When a startup begins seeing success and can afford to buy a better name then in many cases re-branding is seriously considered.