[*]The problem is that you are using the standard character generation rules. It's fine if you use the optional character generation rules. Correct balance should be defined by the standard rules, not the optional rules.
You make it sound like random roll is established orthodoxy while point buy is some kind of suspicious splatbook addition.
Don't expect balance when using random roll.
I don't think this subject should be restrained to a Battlesinger thread, though.
[*]It's fine so long as your ability scores are moderate. Correct balance should consider reasonable extremes - both high and low. By level four Bladesong's AC is equal to the heaviest melee if you roll a 16 and a 17. About 1:6 characters.
Now you're just reiterating #1. And nobod has said it's only fine as long as your ability scores are moderate. It's at low level its broken with high (nay, maximized) ability scores.
[*]It's fine so long as you have more than two combats per short rest.
This can't be directed at me - I'm one of the most vocal people for dispelling the "6-8 encounters easy" myth
[*]It's fine because the best way to use it is to hang back, protected by your AC. This is a separate argument/problem. Bladesong can be over-powered
and it can be best used by hanging back, at the same time.
No, this is at the core of the issue. You are severely overestimating the value and OP:ness of a Wizard's melee abilities. This is because you for some reason refuse to see the opportunity cost.
Compare to the Bard. In 3rd edition it came across as the designers going "okay, so if we make the class 50% as good in three areas that's balanced right since 150% is pretty good right". It turns out that 50% is worthless and could just be 0%.
What a jack-of-all-trades feature needs to lie at is a topic for another discussion, but it's closer to 80-90% than 50%.
Back to the Wizard: the simple fact it isn't a better Wizard than other Wizard severely crimps your OP argument. Yes, other wizards are jelous of the Bladesingers AC,
but that's it. Fighters aren't jeoulus of Bladesingers.
Wizards aren't overshadowed by Bladesingers. Fighters aren't overshadowed by Bladesingers (any more than they're overshadowed by other wizards, at least).
Since nobody is overshadowed, what's the problem?
[*]It's fine because you're only moderately good at melee. Correct balance doesn't make the strongest class also moderately good at melee. And that isn't the only way to benefit from Bladesong.
Not sure if there's a point here...?
[*]It's fine because there are bigger problems elsewhere. This is a logical fallacy. There can be bigger problems elsewhere
and Bladesong can be poorly designed. Nowhere am I extending any argument about the prioritisation of problems with 5e for fixing. I'm talking here only about Bladesong.
Actually none of the rest of us are talking about the Bladesinger, since only you have such big issues with them. The rest of us are talking about you and your big issues with Bladesingers
Humor aside - if you didn't come on so strong you could have had a more nuanced discussion. It doesn't sound like you truly believe there ARE bigger problems elsewhere... which is about the only thing that draws replies to your posts, to be honest.
[*]It's fine because I play one and I don't feel OP. I don't believe I've ever heard a player complain when their class was strong. It is helpful to have anecdotes, but a designer's job is to look at the overall balance of the game.
Correct.
[*]It's fine because Wizards don't have many hit points. This is a decent argument, and one I considered before making this thread. The ability later in their career to trade spell slots for HP is pretty neat, and I wish had been made more basic to the class. But until you get there the high AC actually exacerbates your problem because creatures get down to only hitting on critical hits (natural 20s) at which point the class becomes too volatile. This low HP aspect of the class is a problem, not a solution. One very large issue with the high AC arrangement is how it can be combined with other abilities, such as Shield of Faith or Warding Bond with narrative warping effect.
Don't think I understand "low HP is a problem not a solution". Being "too volatile" (I guess you mean "either well, or dead") is life as normal for a Wizard. Not sure why this should be fixed here, especially since it's a good check against any "melee OP:ness" of Bladesingers...?