If you can't do it yourself, or are unwilling to do so, then for you it warrants a professional service.
If you are able and willing to do it yourself, then for you it doesn't.
I'm confused now Jowwy. If you understand and agree with the points of Alex321 then what on earth is your question? You already knew the answer, it might almost be suggested that you started the thread just to pick a contrary stance to anyone that posted.....
I'll edit my posts below (in BOLD) just to clarify my statements for anyone struggling with the nuances of what I am saying.
Fly tipping is encouraged by the people who refuse to pay [a reasonable price] for the removal of waste by contractors or try to screw down the job to the lowest price or hourly rate ("I'm not pay £45/hr when mi'laddo down the road with a van will do it for £25/hr.......).
There is a huge chunk of society that doesn't want to pay [a reasonable price, covering all the related costs] that, after all who doesn't like a great price? But by doing so they are either ignorantly or by turning a blind eye, facilitating fly tipping.
This is clearly not aimed at someone who has the desire, ability and time to legally do part of the job themselves to keep the cost down, trading their time and effort for a financial saving.
I'm sure, given the option and a great price that included taking away the cuttings if you wanted them to and wasn't any cheaper if they didn't, then you would accept the offer?
Your original example of the £180 for four hours work may initially sound a bit expensive, but in reality, once the back ground costs are factored in (Those 2yr waste carrier licences aren't free you know?) as well as the cost and time of disposing of the cuttings (maybe £40-50 to the site that accepts them, plus probably an hour of the contractors time to travel, weigh in and unload) that £180 is suddenly down to £130-140 and it's not 4hrs work but 5 and hey presto £45/hr is now £25/hr and out of that £25 has to come some tax, some liability insurance, any fuel used, deductions for vehicles and equipment that aren't free and don't last for ever, accountants fees (lets face it, great gardeners might not be top drawer finance bods but still need to file some kind of tax return) and hopefully, just maybe, there might be some money left to take out some kind of wage that pays better than stacking shelves in Tescos!
Like I said way up-thread, some people know the cost of everything but the value of nothing.