ZOS is aware of spammable abilities and their place in common usage, hence their allocation of certain skills to the spammable archetype (which they have acknowledged). As far as actual use of them goes, I think they're waiting to see how they fit in once the standardization of abilities is more or less finished before they work on tuning spammable balance to be used a certain way. As it stands now, I would say it mostly just depends on your build and how you play it, rather than how ZOS intends you to play it. It may also be worth mentioning that ZOS is very aware and by all accounts in favor of attack weaving, which may be what they prefer to have players use to sneak in extra dps rather than using a spammable ability while your buffs and dots are up. I can't say that for sure but it's something worth considering.