As someone who's new to this game and spent a bit of time visiting various local - as I'm lucky to have a few in the area - flying clubs (some more commercial than others) I can say that I've experienced both sides of this and it was a big factor in my final decision in where to train, cost being a close second
The warmest welcome and friendliest environment was without question Xrayalpha's Strathaven airfield. It's a small local grass strip, and if it weren't for the fact that I'd like to go on to get a Night and IMC Rating, and fly aircraft with 4 seats, that would have been the (very easy) decision made - unfortunately they only offer Microlight training (although the C42 is pretty close to a 'real' plane) and anyway it's not really suitable for a PA28 ...
The next best was one of multiple clubs/training schools based at a smaller local airport - the instructor was great, friendly and ultimately if not for the considerably lower cost at a closer (and ironically bigger) airport which is also pretty friendly, I'd have been there without question.
That said there was a couple which echo the experiences others have mentioned in this thread very much the air (no pun intended) of a 'private' club or society with no real interest in taking new members, the oft-promoted 'trial/experience flights' which seem to be the bread and butter of many of these organisations seemed more like a chore to some rather than something they enjoyed doing or in any way encouraging people to want to fly.
Lastly, there's the cost, I accept that flying is not a cheap business - and indeed fuel is probably more expensive in the UK than anywhere else... however there are huge price disparities across the country. A friend of mine trained at a small airfield down south where hiring a PA28 Cherokee is about £99, or £129 with an instructor. I live north of the border and am paying 40% more to train in the same aircraft - and the cheaper one is in better condition, but 240 miles away - so not really practical for training!
Mention even the 'lower' of these prices to people who don't have an interest in aviation or even to those who fly but in the US and watch their reaction..
The aforementioned friend now owns his own a/c, and got support and advice in doing that from others at the airfield... I know people who've made the same suggestion up here to be met with "oh, you don't ever want to own a plane, too much hassle" ... well that it may be, but still - why not encourage people who actually WANT to fly more often, potentially start a new sharing group or similar - surely having more people actively involved in GA is a good thing ?
Unfortunately I have neither the skill, confidence nor patience to become an instructor - otherwise I'd be tempted to try and form yet another club and try to do it differently...
The strange thing is, despite the somewhat frosty welcome at most places, particularly the first I went to, it never deterred me from wanting to get back up there!