If that analogy were correct then the event in question would clearly have not had any demand in the first place and so the touts would make a loss. - they do have to compete with all the other punters so are hardly going to get anywhere near cornering the market for any popular event and will lose money if they tried with an unpopular event.
touts only buy a portion of the total available tickets & like them or not they are providing a service - a secondary market effectively
buy a ticket for a mate who pulls out at the last minute what do you do - sell it to a tout who is effectively 'market making' outside the venue - or sell it yourself tbh.... if you decide to go see a band at the last minute the tout is there ready to offer
the London stock exchange etc.. are secondary markets for shares - what touts are doing isn't any different yet you won't hear many people going "OMG you bought google at the IPO and now you're selling for a massive profit"
If the tickets are not specifically marketed as non-transferable then implicitly there is a market for them - there is nothing wrong with this it is just business!