Pwrsonally I don't see any other coins that are worth daily trading besides Bitcoin.
Is it not strange that after the altcoins bled out the general concept changed from being alt enthusiast to bitcoin maximalists? Its nice to see people change like this and it also brings out the level of hypocrisy that some people have.
Also, day trading is very demanding, it requests a lot of experiences and knowledge and your full attention to the market so it would be very hard to follow this for multiple coins. But maybe there are some successful traders who could manage that also.
Obviously some day traders will be able to make money from trading alts. But know this as well, majority of day traders actually make money by selling their memberships to personal pump and dump groups rather than actually trade. They give their own picks which are again pumped up coins where they are going to dump on their members when they go after that pick and buy it to a huge price.