I suspect the Squeezebox Touch is simply too inexpensive to rate much higher regardless of performance.
A couple of years back the Transporter was rated Class A. I've been a Squeezebox user for about 9 years now and have used everything from the SliMP3 to the Transporter in my home system. I couldn't justify the cost of the Transporter in my system compared to a SB3 with an external DAC (Lavry) so used the latter combo for several years.
When the Touch came out I compared the Touch (with analog outs) back-to-back with my SB3/Lavry combo. The two options were synced and level matched and I more often than not couldn't tell which was playing unless I looked at the input selector switch on the amp. I ended up moving the Touch by itself in my main system, sold the Lavry and moved the SB3 to my second system. I haven't looked back since.
Of course, some audiophiles chase shadows in an ethereal zone that doesn't interest me much. I enjoy a wide variety of music on my system and I've never found myself wishing for a different source. I agree with Tvad - if you enjoy your system, don't waste your time worrying what the elites are thinking.