$100 if you can show where I made such a claim. Calm down and read posts multiple times if needed, before answering. Read other peoples posts as well as you expect people to read datasheets.

Hobbyists seldom use 400 ball chips. But they may need to solder 64 ball chips for the simple reason that the chip isn't available in another footprint. Another important thing is that it is a big difference between 0.5mm pitch and 1.27mm.

I do not recommend people to run out and buy toaster ovens, but there is ample proof that a hobbyist can manage BGA projects. Not claimed to be easy. But claimed to be possible.

For our initial BGA-based design (about three years ago) we did one redesign for the reason that too few PCB manufacturers could manage the tolerances at all, or the premium cost was too high. Mainly because of the alignment requirements. With the initial spin, we had about 90% usable boards. And the solder process was well calibrated and we hadn't any other chips close by that disturbed the process and required a board-unique recalibration so the x-ray images showed a go-ahead from the start.

Since then, the BGA chips have had less faults than the TQFP chips. No pins that could be slightly bent, and optical scans of the balls can detect chips with damaged solder balls before the chip is mounted. At least for prototypes, people will do well to add zero-ohm resistance bridges to all important signals, to allow easy access to them and, if needed, allow patching.