"… let them". Aye, and sometimes let them down.
Buffer – there is indeed, and my own (far too slow) project is a 4"-scale steam-wagon.
Even better in a club not dedicated to one specific branch of the hobby, is a mix of rail, road and Any Other.
This happens here in Weymouth, which over the last couple of decades has evolved from primarily rail (and has a ground-level, twin-gauge track) to a near-balance of locomotives and traction-engines; plus a few members building stationary engines.
I do also belong to a society devoted to road-steam so does not need a railway itself; but further and perhaps unusually among model-engineering clubs, it has no HQ of its own. It hires village-halls for its social evenings, and other venues for running events.
Pros and Cons? It avoids the big financial and physical overheads of large fixed assets demanding constant maintenance, common in large clubs in our and many other pursuits including my home ME society with its track and small club-room, and my two caving-clubs with their self-catering hostels.
Lacking a club HQ does reduce the opportunity for general, informal contact between members; but it also avoids the fear that potential members might have, of becoming lumbered with helping look after a building.
This problem is addressed by many societies organising definite working days / weekends; and those members involved usually find these as enjoyable and constructive as actually using the place for its hobby and attendant social purposes.
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The OP's original fear, of being lumbered with too many public events for comfort, is a different matter and I can sympathise with him on that.
I have enjoyed over many years, occasional portable-track events – give me a garden fete and I'll spot the tea and home-made cakes stall quicker than a Labrador smelling a beefburger – but I would certainly not want to be under pressure to spend one weekend after another driving round and round the club's line.
In fact, these days I am happy to take only a few, informal laps "light engine" round our circuit, which is of decent length; but I will also help look after it.