Some of the headphone amplifiers put out 5 or 6 watts of power. On some headphones, even that amount of power could be dangerous. Speaker taps don't have to be built "in the raw" -- as one can utilize an appropriate resistor on the "+" connection to allow for better protection. Additionally, I see all kinds of members going back and forth between $500, $350, $600 amplifiers ... buying, selling, buying - just to get the right amp and losing money on each deal. The receivers and amplifiers that I'm referring to usually are about $100 to $150 (used) and have a lot of features. Some controls over the tone, a balance control if needed, sleep timers, multiple inputs, etc.
I think good, stereo receivers are far overlooked. Also, as I had mentioned, the Yamaha RX-797 has a great headphone output stage - so, if there's anyone who has a fear of running speaker taps, there is no need for the taps in this case, because the beautiful sound is already there. I'm not into telling people that they should spend $300, $400 or $500 more than they have to, when great equipment can be had for less than the boutique headphone amplifiers. And, I'm not Schiiting you either.