RaytekSorry but I don't see a point in a matchmaking system where everyone will goof off and broken items are allowed. A new players will queue into matchmaking and think pocket engineer with short circuit is "the meta" which is going to suffer from the same problem we have now where people come into 6s and are turned off that their favorite class/weapon isn't used.
"But Valve can just fix the broken weapons!" WAY easier said than done. There are just so many weapons/items that are either broken or useless that it would take months of feedback and out of the box thinking to even fix half of them.
Matchmaking works so well in CSGO because there are no classes or broken strategies used by lower level players that are effective to worry about and balance around. RASH B NOO STOP BLYAT might work well in silver but it is shut down by 1 molotov/smoke in higher ranks. P90 is great if you can't aim but you get headshot and it's over.
Someone can place a mini sentry and no matter how good a scout I am I can't push up until it's dead. I can be the best roamer in the world but if a short circuit engineer is running at me I can't even rocket jump away. A broken strategy meta may very well turn into something that is the most effective but the least fun.
As far as matchmaking goes, everyone at the top will probably be around mid-high open level and if you aren't you can expect either insane queue times + stomping the other team or the great experience of offclassing against bad players.
You aren't taking into account that not everyone that plays this will look at it with a pub mentality. You assume that players will go in with no knowledge of the meta or items that work. Adding a stream list and giving an incentive to win will result in better pugs then you would expect. If all CS players came into the game thinking "I will just click on people and have fun with negev and tasers" then all of CS mm would be trash like your made up version of tf2 mm. But that's not how it works for CS. People watch streams, youtube videos, and put time in to improve at the game, learn the meta and strive for that higher rank.
TF2 won't grow to it's fullest potential if one thing happens. People like you join mm for one game, have a noob on their team running engie at last at the start of the round and instantly give up hope saying "SEE I KNEW IT WOULD BE DUMB!!!! OUR ENGIE IS BAITING US" and give up hope. You need to have faith. Without faith from the upper levels of the comp community the ranks will be a joke, the weapons won't be balanced, and the game won't gain anything from this massive opportunity we are being given by Valve. Go in with an open mind and prepare for the fact that sometimes, just like in CS mm, someone on your team won't know as much as you. But help them. Tell them why what they're doing is hurtful to your team and hopefully they will retain some knowledge.