Why can't existence be mostly good? My question has to do with existence itself. We all know there is suffering in life and that it is due to the fact that fenomena is ever changing, so any state (good or bad) is conditionated and will therefore change. This is what I understand as the number one reason for the pursue of enlightment: reaching the natural, unconditionated and unborn state of (not) being and therefore be released from it. 

However, is this search for the ultimate happiness truly hopeless? I mean, imagine if we were to live a life composed of 99% satisfactory states while just a small percentage of it being actual suffering. Wouldn't that life be truly worth striving for? What I see as a human being however is that people mostly suffer just as much as they feel well. We drink, have a great time and then feel empty and a headache; we might even live and overall very pleasant and fulfilling life but in the end suffer greatly from illnesses... Even from my own experience, I don't seem to be able to have any sort of "breakthrough" of overall life satisfactoriness; it always feels to fall back into the same neutral level and I can't scape this. 

Personally I feel uncertain about enlightment. Something that has no comming back, nothing for ever after, no pleasure, no pain, just blank, not even color or feelings... I would say it is like being a zero. And if only I could live in a better overall way it would be better than zero. It seems to me that being able to live 1000 very good days every 1 bad day is a pretty good trade. Isn't it possible?
Enlightenment &amp; the path to enlightenment (such as meditative jhana) is a higher &amp; better pleasure than any pleasure that can be experienced in ordinary life. 

This is the simple, accurate &amp; correct way to view enlightenment. 

Please refer to this link.


  
  Bhikkhus, there are two kinds of pleasantness. What two? Household pleasantness and the pleasantness of one gone forth. Of these two, the
  pleasantness of one gone forth is better.
  Bhikkhus, there are two kinds of pleasantness. What two? Sensual pleasantness and the pleasantness of giving up sensuality. Of these
  two, the pleasantness of giving up sensuality is better.
  Bhikkhus, there are two kinds of pleasantness. What two? The pleasantness with substratum and the pleasantness without substratum.
  Of these two, the pleasantness without substratum is better.
  Bhikkhus, there are two kinds of pleasantness. What two? The pleasantness with desires and the pleasantness without desires. Of
  these two, the pleasantness without desires is better.
  Bhikkhus, there are two kinds of pleasantness. What two? Material pleasantness and immaterial pleasantness. Of these two, immaterial
  pleasantness is better.
  Bhikkhus, there are two kinds of pleasantness. What two? The noble pleasantness and the ignoble pleasantness. Of these two, the noble
  pleasantness is better.
  Bhikkhus, there are two kinds of pleasantness. What two? Bodily pleasantness and mental pleasantness. Of these two, mental
  pleasantness is better.
  Bhikkhus, there are two kinds of pleasantness. What two? Pleasantness with joy and pleasantness without joy. Of these two,
  pleasantness without joy is better.
  Bhikkhus, there are two kinds of pleasantness. What two? Pleasantness on account of agreeability and pleasantness on account of
  equanimity. Of these two, pleasantness on account of equanimity is
  better.
  Bhikkhus, there are two kinds of pleasantness. What two? Pleasantness on account of concentration and pleasantness on account
  of distraction. Of these two, pleasantness on account of concentration
  is better.
  Bhikkhus, there are two kinds of pleasantness. What two? Pleasantness with joy for an object and pleasantness without joy for
  an object. Of these two, pleasantness without joy for an object is
  better.
  
  
  Bhikkhus, there are two kinds of pleasantness. What two? Pleasantness on account of an agreeāble object and pleasantness on
  accout of equanimity for an object . Of these two, pleasantness on
  account of equanimity for an object, is better.
  
  Bhikkhus, there are two kinds of pleasantness. What two? Pleasantness born on account of a material object and pleasantness
  born, on account of an immaterial object. Of these two, pleasantness
  born, on account of an immaterial object is better.
  


As for your other concerns, they are unrelated to Buddhism. Buddhism is not for people who believe ordinary life can be pleasurable most of the time. Buddhism never ever states all people must follow the Buddhist way of life.