Support them if they propose something useful. Namecoin, a scrypt coin, a coin based on the prime algorithm, these are interesting. But a bitcoin clone whose difference is only a different name? lol
Agreed. The ones with meaningful technical distinctions contribute to making the crypto ecosystem better. Bitcoin shouldn't incorporate innovations without lots of testing and debate, so alts serve a very valuable experimentation function, even in the bitcoin-centric viewpoint.
I just wish alts that are effectively clones of bitcoin (ie, with just the mining alg, issuance curve, or block times changed) would die faster. To the crypto-ignorant masses, having hundreds of alts makes the whole crypto space seem silly.