When I play chess tournaments and I have 5/2/2 in the tiebreaks I always lose to players with 6/3/0. So why is a win better than 2 draws? Which is the logic behind it?
The criteria used for tiebreaks is indicated prior to the tournament and figures in the tournament's reglementation that is supposed to be available to all participants.
There are many systems used for breaking ties : cumulative score, score of opponents calculated in various fashions (Buchholz, Sonnenborg-Berger...), rating perfomance, and one of them is the number of wins. I assume the tournaments you played used the number of wins.
No tie-breaking system is perfect and debates about which is the better are endless. The rationale behind using the number of wins is to reward more entertaining play (which might result in +1 -1 rather than =2) and (slightly) discourage non-combative draws. This was especially thought to be a nice idea at a time when (high-level) chess was plagued with too many draws.
One of the consequences is the attribution of the 1988 World Junior Champion title to Joel Lautier in front of Ivanchuk, Gelfand and Serper who had scored as many points but less wins.