I agree that the overwhelming majority of posts about low cost airlines here are negative, certainly the impression I get.
I am a huge fan of easy, Ryan and Go (charging for reading CVs notwithstanding...but I bet they get a lot of crap to sift through and the £50 is more of a filtering process than a genuine revenue-raiser). They give people what they want, and in the short/medium airline business that means a seat at the cheapest price. Agreed the £5 fares don't make money but that's not every seat (4 per a/c more like), so if you call and the cheapest one-way that's available is still only £39 or £59 each way, it's still tonnes better than BA or BD (whose £99 "offers" evaporate as fast as the £5 offers at easy/Go/Ryan: £5 at e/G/R = £99 at BA/BD, £39 at e/G/R = £189 at BA/BD, £99 at e/G/R = £459.80 at BA/BD). All my flights with low cost airlines have arrived within 30 mins of schedule, which is the only other factor (other than ££) that matters.
I used to think the advantage of paying £300 to Europe on a mainline carrier was industry clout, ie accepting odd-size cargo (guitars in my case), accomodation due to canx etc but I had a problem with my Portugese visa (I'm an Oz) and Go put me through to the Portugese embassy from their ticket desk and were very knowledgable about a fairly complex situation, which was probably more help than I would have expected if I was flying Business Class on, say, Luftansa. And in fact easy and JEA/BEA have both gone above and beyond to accomodate musical instruments (and an antique gramophone, once).
In my experience low cost airlines do exactly the same as mainline airlines except the meal (and you can still buy one onboard if you are feeling snacktacular), at a much lower price and should be supported by the industry the way they already are by any passenger who is (a) paying for their own ticket or (b) has their fare paid by a company that allows employees to fly with a certain airline regardless of the cost, so said employee can rack up points to take the family to Florida. If easy had a FF scheme which built points for Virgin flights to the likes of MCO and SFO, BA's European network would close in a week - I'm convinced it's supported only by the staggeringly high £600 to Vienna / £900 to Athens Club Europe fares, paid by FF card-yielding business travellers whose employers don't have a strict travel policy).
Give em the slots and let em make money.