I think Giffgaff should create two different £5 goodybags. One can stay the way it is and the second one should include mins and txt only. The reason being is some people may not use data at all and may need more mins and text. For example the elderly generation. Buying a £5 package is a waste for them if they do not use data at all.
The £5 goodybag was originally minutes and texts only. giffgaff added 20MB of data (which has slowly increased over time to 100MB) because members asked for it.
Very low users could be better off using standard PAYG credit instead of goodybags. A goodybag could be added at any time should higher than normal use be anticipated.
I suspect @zarakhan99 that giffgaff likes to keep their tariffs simple. A few months back they had two different £10 goodybags with different allowances, however this resulted in a few people buying the wrong one. Having only one goodybag at each price prevents this happening, albeit there is still some confusion between the £5 goodybag and £5 gigabag.