Core is saying that because their agenda is to push people off-chain onto their LN.  Gavin was right on that one.  There is NO technical problem with big blocks, but there is a huge economic problem with it if the block rewards run out.

But the LN is dangerous on block-limited systems, because for the LN to be inherently safe, ALL channels must *at any time* be able to settle.  If settlement is limited (by limited blocks), then the LN becomes unsafe.

So it is somehow ironic that Core is pushing for a LARGE LN on a SMALL chain, because that constellation is what makes LN unsafe.  LN would be perfectly safe on UNLIMITED block chains - but then, nobody would use it apart for specific applications like your link to your exchange, but where "multi-hop" links are not needed.