I think this depends on someone defining gambling for himself. yes, as you said. no gamble is wasted if one does not gamble only for profit. but some others, have a different definition to what you say. maybe for others, making the profit is part of the fun. therefore, they say that no gamble is wasted. yes, regardless of winning or losing. that gamblers must be well aware of every risk.
Also, the word have fun often becomes a trap for gamblers. that too, which makes gamblers fall into addiction. if, not based on responsibility and understanding of gambling itself. however, actually I agree with what you said. that every bet we make, provides a new experience and every gambler gets it in a different way. well, maybe these words are more appropriate to be associated with no wasted bets.
Being aware on the risks or being aware on how much money that you could potentially lose if you bet and the bias did not materialized is very important because it helps you and your mind to be prepared in that kind of scenario. If you already foresee it before, then you will not experience any negative emotions. Those professional gamblers have these kind of skills wherein they are aware that anything can happen so they embrace the risks wherein they will stay in neutral state even they have consecutive losses in gambling.
Seeking fun should be the goal in gambling, you cannot do it if you do not fully accept the risks. I really do not recommend someone else to play gambling especially if they are not risk taker and if they do not understand the odds and probabilities of making money.