Consumers have little need for vendor-specific coins
I am not an economist, but a lot of vendor-specific crypto sounds like Trading Stamps, Coupons, or maybe even Company Scrip. These might be better called "vouchers" or "tokens" than "coins". There are financial incentives for a company to issue such a token:
- It aids the issuer as a barrier to competition in that industry (a Banana-voucher might only be good for purchasing one brand of bananas).
- An ICO can temporarily increase a company's stock price not just because of the lock-in, but because it's trendy.
- Issuers can also dispense currency in amounts that allow them to keep-the-change (Shutterstock and gift cards currently do this). If hot dogs and pony rides are $3 each you can choose sell tickets in lots of $10 and keep the un-redeemed ones as profit.
Consumers may appreciate some market-specific coins.
The Emissions Reductions Currency System might be an example of a market-specific coin being used for good. It might be better classified as Representative Money backed by the right to produce emissions? I wonder if a proof-of-identity blockchain would benefit from identity-specific tokens that have no other value than to indicate who you know and whether you trust their identify?
Maybe something small scale could work to the customer's and company's benefit the way coupons enable people with more time than money to purchase things they couldn't otherwise afford?
We will probably always have multiple cryptocurrencies
Many cryptocurrencies have technical differences. Hash functions have a lifespan, so coins with different hash-functions will break at different times. Coins requiring different mining hardware encourage decentralized production. Proof of work avoids DDoS attacks, but proof of stake may use less energy. Virtual machines running in some blockchains allow processing power to be traded, but for security reasons, some people would rather not have other code running on their machines. Some coins do a better job of ensuring privacy, while others might favor accountability.
The governance of these coins is very important as well. Most of these coins are made by people working together. There are new rules for trust (open-source code, proof of work, proof of stake, etc.) but it still all ultimately relies on people working together.
Some coins may have properties that favor wealth accumulation, like a limited supply. Others may favor spending/exchange and be tied to a government-issued currency.
I think everything in this section benefits the consumer and often the investor as well.
Industry or vendor-specific coins tend to benefit the industry/vendor in the short-term and only occasionally the consumer in the longer-term. Vendors with a sufficient lock on their industries can get away with working for their own benefit, but I'd be more excited about owning their stock during the ICO than I would be about buying the coin (or their stock after the announcement).
There are technical/governance reasons to have multiple coins/blockchains, but I think the most successful coins will be general purpose currencies, not vendor specific ones.
An economist might be able to answer you with a single link that made all of this clear and had a litmus test to tell whether an industry-specific coin is necessary for the consumer, or only to benefit the controller/producer.