That wouldn't eliminate the problem. Demand changes over time, and supply is fixed. There are quite a few ways to invest in tickets. One is to buy all the tickets on an event that is expected to sellout immediately. Another is to find an event that you expect to sellout at some time before the event that will allow enough time for demand to build, and you buy tickets before it sells out. In the end, ticket prices change over time, therefore there will be a market. Even if the primary seller (e.g. TicketMaster) raises prices, if you bought at a time when they were cheaper, you can resell at a profit.
Event ticketing is a market, and as such there will be people that want to invest (even if it's just fans who intended to go and then decided they couldn't, or the money they could get for the tickets is too much to pass up). Scalpers (brokers) provide a service, liquidity. Often they go too far, and use technology to get tickets in unethical ways (ignoring site policies, bypassing captchas, using software to tie up thousands of tickets they have no intention of buying, etc). But the fact that they continue to exist is because there is demand (and now TicketMaster is in on the game as well, their TM+ service allows you to resell tickets on their site along-side their own, unsold tickets).
