This is hands down my most favourite game of all time, however, I feel that I can't recommend this fantastic game to any new player at all.
The game is filled with hackers and bots as many people have talked about a lot, but there are many aspects of the game that feel targeted towards making the game really un-fun as a new player.
Mechanics such as random crits which always work in favour of the players who have dealt more damage, and the frankly absurd crafting system and in-game item shop, which make certain weapon unlocks look far better or far worse than they actually are with incorrect or missing stats, and make certain weapons, which are sometimes direct upgrades to their stock counterparts very difficult to obtain.
There are also many weapons that feel almost designed to work much better against new players, even if they are widely considered to be bad. Weapons such as the direct hit (which usually rewards player skill with bonus damage) can severely punish new classes that pick scout or spy for instance. These new players won't understand the concept of damage ramp up, and they also wont have very good movement or positioning. This leads to the direct hit soldier getting a massive advantage regardless of skill. Weapons such as the Eyelander are balanced around good players being hard to kill with melee only and reward good players with bonus health and move speed. These benefits are usually capped behind an otherwise worse option to stock, and get much, much better when there are tonnes of new players around that don't know how to deal with even an Eyelander demo.
There are many other examples that I could have mentioned as well, but the core problem with TF2 for new players is also one of the greatest draws of the game for experienced players, and that is the game's incredibly high skill ceiling, which is easily my favourite aspect of the game, but is also incredibly punishing for new players, who, when faced with even a few amazing players on the apposing team can almost be completely unable to play the game or have fun. This is an issue that even moderately well experienced players can face when playing against veterans, although then the interaction makes more sense to the less experienced player, and they may even find it fun as an additional challenge or potential for improvement.

My biggest reasons for recommending my favourite game to all my friends are the same reasons why I love the game so much, a incredibly diverse range of interesting and complex classes, unlocks and mechanics, and an unfathomably high skill ceiling for them all.
In conclusion, regardless of the current situation of the game (which makes all these problems 1000 times worse) TF2 gets more and more fun to play as you get better at the game, which results in an incredible, and completely unique masterpiece for well experienced players, and a hard, unforgiving, weird and complicated game for new-comers, but once you get a few hundred hours under your belt, man, is it a great time.




(I would change my review if the game was currently in a better state, and if a few of the more severe issues were fixed, but I would never want the skill ceiling of this masterpiece to ever be lowered in any way :p )