Kind of rubbish though for say your average one-man-band turnover so an average tradesman / professional turnover, because the difference between tax paid as a Sole Trader - Limited Company isn't actually significant between the two, what is significant is the legal entity of trading, such as the exposure of personal assets, and as others have said, the requirements of customers of the service.
The difficulty of a sole trader as limited company is setting the salary to an extent of having money in the bank to pay it each month. For many it is about cash flow, and it is much easier to operate on a low salary keeping cash in the company as long as possible for potential fluctuations. The government prefer the limited company model with the company bank account and stricter accountancy rules, because of the loop holes sole trading gives you.
Out of all the people you can take a pop at with regard to tax affairs, your average 1 man band as a limited company operating perfectly and reasonably within the rules as set should not really be one of them. All this 'crying now' because they may have saved a couple of £100 here and there in tax just comes across as a bit misguided.
A couple of hundred here and there - Yeah Right - It is thousands every year for each business