This is a terrible attitude because in a league it isn't all about you all the time. Competition is healthy and without it a league will fold. You need healthy competition for a league to thrive. Sure it might be nice to blow everyone out every year but eventually they will stop playing and the league will go away.It is your responsibility to do whats best for your team, if it is within the league rules, do what you have to do to make your team more successful in the future. Pretty cut and dry. Just because you dont like something doesnt mean its wrong.
Tanking is a the biggest culprit to competitive imbalance there is. Most of my leagues have a schedule set up where you play everyone one time and if you happen to play against a team early that is trying and then the guy you are tied with plays that team late with 4 bye players in the lineup how is that good for the league?
In no circumstance should a team ever play someone on bye (let alone multiple players). That is just being lazy and purposefully hurting the competitive balance of a league. Just because there may not be a specific rule stating not to play players on bye everyone knows the intent of the league is to not do that. Just because you can doesn't mean you should.
When it comes to tanking your last statement is wrong. Nobody likes it and it is very wrong.