Why can't sidechains fix the problem?

I'm thinking all this BTU crap is doing a lot of harm to Bitcoin. And worst. This is going beyond what Satoshi designed. Hell, why just can't we increase the Blocksize as Satoshi himself proposed from the beginning??? And if not, instead of segwits and all that crap that is seriously destabilising the community why not use Sidechains??

New people thinking in getting in now must be thinking... what's all this fuss around hard forks and stuff... basically what it is doing is scaring away newbies and big investors alike.

I mean we already have the altcoins and to me, they act like side chains... The transaction time is increasing and a lot of people is fleeing to the most promising alts.
Now with all this BTU crap we might see bitcoin losing a lot of weight.

Just saying... why shouldn't we go for sidechains to solve this?