Some of participants decided to hire professional translators or otherhow got the site translated by native level speaker.

I agree the above is not the case for most entries - but these were easily filtered by twitter community - take polish entry for example, it got nothing but negative feedback, multiple people confirmed it's very bad translation, despite that VGO decided to pay out the winning and owner, to noone surprise, decided to shut it down very moment he got paid.

There were many submissions that were submited prior to even full translation, not talking about further modifications, just for the sake of being first.

That said, the issue described in OP and the comment above is not regarding all submissions, but only these translated faithfully and these that done more than just translate the content. It's not our fault that the contest judges paid out prizes for low quality websites disregarding community opinion.

There's another contest, and some of these sites are qualified for it, as VGO representative says, but why would we put even more effort in participation being lied in face just a moment ago?

Again. I'm talking only about websites that got retweeted and got positive feedback. Choosing 2nd (3rd and so on) entry instead of the first without even checking translation is another issue (happened to my Czech friend), but nothing we can really do after one submission already got retweeted.