ETH is much more popular and useful than ETC. But yes, you can invest a small part in it as a diversification strategy and hope for a bull run in future. But don't invest a big part of your income in it. It's just not worth it.
True. I would say its not even worth investing a penny in ETC because of its history as we all know that ETC was hacked and in order to compensate the amount lost by the investors and to improve the security system hard fork called Ethereum was launched.
Why would people even wanna go back to old technology that isnt even worth? There are far many better projects in the market now such as NEO, ADA and WAVES that have smart contracts and advanced technology.