Having seen one level four card major suit responses hundreds of times before, many players don’t think twice when the opportunity arises. This habit can lead to awkward rebid situations when holding a longer minor and a good hand. Consider this holding …
AQxx J Axx KQJxx
Opener bids 1H and you bid 1S, as usual. When opener rebids 2H responder is in a pickle - clubs may be the right strain but there is no way to show this economically without also suggesting you have longer hearts!
This problem mostly goes away by starting with a 2C response, planning to rebid 2S. This principle also operates after a 1D opening, but with some additional nuance resulting from 1D - 2C possibly being less than game forcing, see here for details.