I always click 5stars on Felix's sounds btw . Just to give thumbs up to the quality and character of the sounds he uploads. Kudos.
Than there are sounds that are really shitty where I feel I'm obliged to give 1-star rating to warn potential downloaders with bad monitoring (or unexperienced to hear the "quality").
Displaying the star rating only after 5 or more ratings would be elegant... if only downloaders would rate the sounds more often. It's not uncommon to have some sound downloaded 1000 times and get no comment, rating or atribution.
Good and wise rating system - creates healthy environment. Take the Bandcamp for example - they offer "tell your artist why you like this track", and nor "rate this track". And healthy environment - creates better social interaction, and better desire to share something good.
Ratings certainly have limitations on usefulness. Freesound could keep track of all ratings a particular user has given, then dynamically compute the contribution of each rating instance by its giver's spread, with the result being a new type of rating (an "adjusted rating"). This could use both weighting and translation of values in determining any items overall adjusted rating. Since this could be a bit expensive computationally to do on the fly, it might be done daily or so with a batch job. For example, a user who has only ever given 2 ratings out might not be given much weight to those ratings in determining the adjusted rating of the rated items. Once enough are given out, then the spread and distribution can be taken into consideration, and each instance adjusted to make it cover a broader spread, perhaps even across all 5 values. The drawback here is that if a user has given out 10 ratings, and all are 4 or 5, do you then map those to 1 and 5? Obviously, that would be bad. That user probably only rates when the rating would be good. So I'm not sure how to really make it work.
I agree - it's meaningless: ratings have a different subjective meaning for every user. And it creates many perverse effects like you say. Eg if a sound has a five star rating, and I genuinely think it's a four star sound then I probably won't leave a rating because that would lower the average score for the user! Maybe those who upload sounds think differently about ratings from those who only download.
Moving to a LIKE system would allow people to recognise the contribution of sound creators in a positive way. It supports the old adage of 'If you can't say something nice about someone then don't say anything'. If people want to be critical of sounds they should do so, without the protection of anonymity, in the comments - most sound creators have no problem with sincere or constructive criticism. But if they do then they can simply delete the comment, which restores the balance of power in favour of the sound creators.
A "like" system would be great. If you like it, you rate it, and if you don't, you don't rate.
I personally never look at ratings because it is fairly easy to simply heard something right from the search page (instead of having to open the individual sound's page).