Where is the real problem?

So now even the PM and his deputy are at it - pledging to do more to stop tax avoidance by large companies.  I am totally fed up with making the point that tax avoidance is perfectly legal, but I think what Cameron and Clegg are saying goes further than that and raises more questions.  Cameron in particular is having a go at the use by large companies of "fancy corporate lawyers" - in other words the case he is seeking to make is not a legal but a moral one, that it is unfair that large companies can afford to employ said "fancy lawyers" to find loopholes in tax legislation for their clients, whereas Joe Bloggs cannot.  Of course what underpins his comments is an unspoken acceptance of the fact that tax law is so hopelessly esoteric and complex that there are bound to be loopholes for those clever enough to find them.  Perhaps he should direct his efforts more to making tax law simple enough that we can all understand it and the fancy lawyers become surplus to requirements, and then the moral problem he perceives would cease to exist.