In fact, most people don't even need a level 2, though it does offer a bit of convenience. Those with longer commutes may benefit, but frankly a level 1.5 charger (3kw, for example 240v @ 15a) is good enough for probably 95% of drivers. So people are skeptical of anybody wanting a level 3. Even the smallest level 3 such as a 20kW. (There is a 7kW level 3 charger, no faster than AC charging, mainly meant for people who dream of V2G and bidirectional charging, not possible on current Teslas.)
The negative reaction comes because usually desire for a level 3 charger indicates gasoline thinking, that you are "doing it wrong." There is a very tiny subset of people who might need level 3, and if you are in that tiny subset, it is recommended you explain why you are so very unusual and then you will get people trying to help rather than point out that you probably are mistaken in wanting it.
The small subset might be people who have multiple vehicles that use more than 60kWh per day in them, who live in a remote area and somehow drive their cars more than 200 miles per day while staying in that remote area. Perhaps somebody running a large farm with large electric farm machines that use up 60kWH halfway through the day and need a charge. Or somebody with a giant solar farm as well and no grid power, so they need to charge only when it's sunny and do it fast, since they can't really charge at night without having huge batteries. These are the sort of things that might need a level 3 charger. For almost everybody, if you are driving so far in the morning that you need a fast charge later in the day so you can drive super far in the evening, you will be passing by many existing fast chargers, and it's simpler to use those rather than build your own, even at their higher price, for most people.
You can get a 25kW DC charger for a tolerable amount of money, and 400a service can power it. But it is best if you explain why you calculate that you need that. One reason might be that you are very forgetful, and sometimes you forget to plug in at night, and so you wake up to a low car and have to leave. That's a time where having 25kW at home would be handy. But better to just make a little program that pings you if you haven't plugged in your car by 10pm -- in fact it would be nice if the Tesla app did that for you already.