Spells that should be rituals or cantrips.

[Kzach]

It doesn't answer it for me. I like the standard Knock spell, it is actually worth a spell slot.

There is no 'standard' Knock spell...

 

[LordGraz'zt]

I may be wrong - but I am sure I saw somewhere that Mearls said any spell could be cast as a ritual.

I think this was an idea they had or similar.

I like it a lot, it keeps things simple (no need for each spell to be tiered) and allows casters to get mileage out of their non-combat and non-healing spells