To be fair, unlike fuel where 75% of the pump price is tax, the government takes only a very small portion of the inspection fee, with the bulk of it going to the testing station (which is partly why many garages charge less than the full amount, offer free re-tests, etc.).
It's interesting to note how the government says the increased maximum fee is to compensate garages for the fact that an inspection is now taking longer to complete. The tests are only taking longer because the government keeps adding more and more petty things to the inspection!
As for the computerization of the MoT inspection, it seems to be turning into something of a farce.