The words might be crap; it's situation-dependent. It depends what you are listening to, how loud and on the specs of your system.

One use case is heavy metal music. This music has a low crest factor and if you listen to it loud, you might need an amp that is beefier than you thought. Say you buy an amp that is designed for 100W, 20dB crest factor continuous, into an 8 Ohm/45 deg phase angle load. If you listen to heavy metal music at 100W, with a speaker of that impedance, the amp might shut down or the output transistors may cook if their power dissipation exceeds their safe operating area.

Another use case is improper matching of components. If you plan on using that amp with M80s, you'll need a whopping 436W at maximum gain to maintain linearity. This calculation is based on Soundstage measurements of M80v2s which are around 3.5 Ohms/45 degree phase angle between 20 and 900 Hz. Above 900 Hz, they are almost purely resistive.

Depending on how the amp is designed, it might shut down or the output voltage will sag. The effect of sagging voltage is audible distortion.

The matching of speakers to an amplifier shouldn't be over-looked for those who like their audio loud. I'm quite satisfied with how well my M80s are matched with my Onk at "low" listening levels. When I turn them up however, the bass and mid-bass simply gives up. When I substitute my buddy's much cheaper KEFs, the bass is full, tight, punchy and controlled at that higher volume (the KEFs have other problems though so I'm not saying they're better).

Now is that an Axiom problem or an Onk problem? It's neither; it's a system problem. It's not even really a problem because I have no need, other than playing around, to turn them up that loud.